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ChaosInc
2005-Jan-29, 04:30 PM
Folks here seem to be rational in their thinking so I thought I would send one up the flagpole for comments: I am in the market for an automobile (for my daughter; yes, I am old). I have been debating the issue of hybrids. One of the autos I have looked at is the Honda Civic. The Civic is a bit pricey compared to its competitors, but is also offered in a hybrid model, that is even pricier.

Two questions come to mind. The economics at present US gasoline prices make the extra cost of the hybrid a breakeven proposition over the life of the car. Is it worth the extra money? The second question is a bit harder to grasp. Does the hybrid make overall energy sense, that is, will the total energy required to produce the extra hybrid parts and dispose of the parts when worn-out be less than the energy saved in fuel reduction?

I have to say that I like the idea of regenerative braking, but owners Iíve talked with donít seem to get as much of the improved efficiency as advertised. I suspect that their driving habits contribute.

Moose
2005-Jan-29, 04:39 PM
Two questions come to mind.

In my mind, three.


The economics at present US gasoline prices make the extra cost of the hybrid a breakeven proposition over the life of the car. Is it worth the extra money?

Hard to say. If you're only planning on driving the car three years, then either "probably not" or "doesn't matter". If you're planning on driving the car into the ground, then it depends on how durable it is and how much maintainance costs over its lifetime. I suspect it'll be significant.


The second question is a bit harder to grasp. Does the hybrid make overall energy sense, that is, will the total energy required to produce the extra hybrid parts and dispose of the parts when worn-out be less than the energy saved in fuel reduction?

Should average out in the long run, I think, unless the batteries are especially more difficult to recycle/dispose of than regular car batteries.


I have to say that I like the idea of regenerative braking, but owners Iíve talked with donít seem to get as much of the improved efficiency as advertised. I suspect that their driving habits contribute.

You're probably right.

The third question I have is this: how well do the batteries function in cold country? Canadians live four or five months in below freezing weather, with most of that between 0F and -20F. Engines are also more difficult to start when they're cold. How do hybrids deal with these issues, or are they a fair-weather car?

W.F. Tomba
2005-Jan-29, 04:53 PM
The third question I have is this: how well do the batteries function in cold country? Canadians live four or five months in below freezing weather, with most of that between 0F and -20F. Engines are also more difficult to start when they're cold. How do hybrids deal with these issues, or are they a fair-weather car?Well, my mother recently gave me her 2003 Prius and I took it out here to Iowa in the middle of winter. It was very cold during the trip and the week after I arrived, and I'm keeping it outside, but it seems to be holding up OK.

I have now driven it from Iowa to Maryland and back. It got about 47 mpg going east and 43 going west. (The difference may be due to Iowa's higher altitude, or colder weather on the trip west.)

Of course the car is a great deal for me, since I save all this money on gas and I didn't have to pay for the car! 8)

Glom
2005-Jan-29, 04:54 PM
All the reviews I've heard say that they are overhyped. They don't give the massive increases in economy advertised and they have poor performance.

I'm still not convinced from a thermodynamic standpoint. Regenerative breaking can't recover all the energy extracted from the battery so it seems like they are a bit like Woking's fuel cell. (We don't use natural gas. We use hydrogen extracted from natural gas. That's much better!)

Get a Micra.

ChaosInc
2005-Jan-29, 04:58 PM
Yes, the durability question is also a sticky proposition. Plusses are that the gasoline engine runs less often and therefore should last much longer, and there may be times when the motors would allow the car to limp into a service station in case of engine trouble (doesnít seem too likely though). The disadvantages of an overall much more complicated system probably will outweigh the advantages, maintenance wise.

I think the Civic uses an ultra capacitor (spell?) in lieu of batteries. What would be the difference?

Kristophe
2005-Jan-29, 04:59 PM
My father has a '99 Toyota Corolla which, according to him, gets ~40 - 45 mpg on the highway. It's a 4-cylinder, with a small gas tank. At $.80 pre litre, it costs ~$35 to fill the tank. My father is known for grotesquely overstating things, though, so take that with a big ol' halite stone.

Captain Kidd
2005-Jan-29, 05:01 PM
Get a Micra.
Sure! If you pay for the transatlantic shipping and import cost. :D

(They're not for sale here from what I can see.)

Glom
2005-Jan-29, 05:03 PM
Plusses are that the gasoline engine runs less often and therefore should last much longer,

It depends how much the petrol engine would cut in and out during the course of the journey. Repeated cycling isn't good for longevity.

W.F. Tomba
2005-Jan-29, 05:04 PM
Regenerative breaking can't recover all the energy extracted from the battery so it seems like they are a bit like Woking's fuel cell. (We don't use natural gas. We use hydrogen extracted from natural gas. That's much better!)Yeah, I suspect the regenerative braking doesn't actually add much to the car's efficiency. The fact that the gas engine shuts off when you release the accelerator is probably more important. But I have a limited understanding of these things.

Glom
2005-Jan-29, 05:11 PM
The gas engine shuts off when you take your foot off the gas? Hmm. That sounds like a pretty rough way to treat an engine. As I say, constantly throttling it up and down is not good for longevity.

Captain Kidd
2005-Jan-29, 05:16 PM
Braking like that is a fairly proven technology. Railroads have been using a version of it for around 50 years. Called dynamic braking, the traction motors act as generators and the current is then passed throgh resistor banks, with a fan to expel the heat. (For those interested, here's an article about it (http://www.trains.com/Content/Dynamic/Articles/000/000/003/079uwrak.asp).

On locomotives the generated enegy is waste and expelled as heat. (Although I think electric units might pass the energy back into the overhead wires...) The car companies just divert that energy bac into the storage medium. General Motors also builds locomotives so they have experience in this, although they're looking to sell that division off.

Doodler
2005-Jan-29, 05:16 PM
I read back when these things were first introduced that hybrids tend to lose their advantages in long range driving. They do better in cities and dense suburbs where lower speeds and constant breaking keep the batteries constantly charged and the gas engine offline. Once you're on the open road, you're probably not using the brakes much at all and you're gas engine will eventually end up working alone. Once you're at that point, bye bye gas mileage. Just a note, that particular nugget of info was admitted to by a Toyota rep. They weren't trying to hide anything about what people should expect from the hybrids, which is why their initial launch was targeted at places where their advantages would stand out. Major cities, particularly on the west coast.

Right tool for the right job.

W.F. Tomba
2005-Jan-29, 05:17 PM
The gas engine shuts off when you take your foot off the gas? Hmm. That sounds like a pretty rough way to treat an engine. As I say, constantly throttling it up and down is not good for longevity.
Well, I don't think it shuts off entirely, but I see your point. These cars are so new, their longevity is a real question mark. They have been on the market longer in Japan, though.

ChaosInc
2005-Jan-29, 05:19 PM
I think the regenerative breaking is the main reason for the improved (city) fuel efficiency. I think that regular friction brakes are employed for high gee stops which tends to negate the regenerative effect. I believe that you canít get the mileage without changing driving habits.

W.F. Tomba
2005-Jan-29, 05:20 PM
I read back when these things were first introduced that hybrids tend to lose their advantages in long range driving. They do better in cities and dense suburbs where lower speeds and constant breaking keep the batteries constantly charged and the gas engine offline. Once you're on the open road, you're probably not using the brakes much at all and you're gas engine will eventually end up working alone. Once you're at that point, bye bye gas mileage. Just a note, that particular nugget of info was admitted to by a Toyota rep. They weren't trying to hide anything about what people should expect from the hybrids, which is why their initial launch was targeted at places where their advantages would stand out. Major cities, particularly on the west coast.
This is definitely true. I have sometimes noticed that when I get stuck in a traffic jam on the highway, my gas mileage goes way up!

Glom
2005-Jan-29, 05:27 PM
So the solution is simple. Everyone get two cars; a hybrid for urban driving and a fast car for long range driving. That will satisfy the environmentalist, won't it? :o

Doodler
2005-Jan-29, 05:30 PM
The gas engine shuts off when you take your foot off the gas? Hmm. That sounds like a pretty rough way to treat an engine. As I say, constantly throttling it up and down is not good for longevity.

I doubt it shuts off completely, more likely its put in neutral while the electric engine takes over. Its still idling, which is why you still burn gas at slow speeds while the electric is working, but its probably not doing more than turning the alternator.

Moose
2005-Jan-29, 06:01 PM
So the solution is simple. Everyone get two cars; a hybrid for urban driving and a fast car for long range driving. That will satisfy the environmentalist, won't it? :o

I don't know about the environmentalists, but the car companies will love it.

W.F. Tomba
2005-Jan-29, 06:16 PM
So the solution is simple. Everyone get two cars; a hybrid for urban driving and a fast car for long range driving. That will satisfy the environmentalist, won't it? :o

I don't know about the environmentalists, but the car companies will love it.
Actually, it seems like two or even three cars per household is already pretty common these days. Any idea where I can find reliable statistics on this?

Kristophe
2005-Jan-29, 07:08 PM
We own 5... 8-[

frenat
2005-Jan-29, 11:57 PM
My father has a '99 Toyota Corolla which, according to him, gets ~40 - 45 mpg on the highway. It's a 4-cylinder, with a small gas tank. At $.80 pre litre, it costs ~$35 to fill the tank. My father is known for grotesquely overstating things, though, so take that with a big ol' halite stone.

I owned an 85 Toyota Corolla hatchback. In the city I got 30-35 mpg but if all highway I got 45.

Togusa
2005-Jan-30, 02:24 AM
The gas engine shuts off when you take your foot off the gas? Hmm. That sounds like a pretty rough way to treat an engine.
Not really. From the info sheet found here (http://john1701a.com/prius/prius-infosheet.htm):


Frequent Gas Engine Restarts are not harmful

Rather than just using a small motor to spin the gas engine to only 100 RPM, like traditional vehicles do, the [Prius] hybrid system uses a much larger motor which spins the gas engine to a minimum of 800 RPM. Then it waits until oil-pressure is established before injecting fuel and producing a spark. This process enables a very smooth startup, reducing burden on bearings, pistons, and cylinders.
About the battery:

Should average out in the long run, I think, unless the batteries are especially more difficult to recycle/dispose of than regular car batteries.
The nickel-metal hydride batteries used in modern hybrids like the Prius and Civic Hybrids are almost completely recyclable, and contain no heavy metals that can harm the environment.


The third question I have is this: how well do the batteries function in cold country? Canadians live four or five months in below freezing weather, with most of that between 0F and -20F. Engines are also more difficult to start when they're cold. How do hybrids deal with these issues, or are they a fair-weather car?
You may wish to read this thread (http://www.priuschat.com/forums/starting-in-the-cold-vt6664.html) on the PriusChat.com discussion forums. Some of the posters there report being able to start their Priuses in -40įF weather. :)

jaeger
2005-Jan-30, 02:33 AM
I had my Toyota Prius over three years now. I live in St. Louis and generally average about 50 mpg in summer and about 43 mpg in winter. Have not had any problems except that the tires wear a little faster because the car is heavier and the tires are a softer compound. Over the life of the car - probably about 6 years - I'll do slightly better than another car I would have such as Camry when looking a mileage and gas costs. If gas costs go up, the better I'll do in gas costs comparisons.

I bought my Prius for two other reasons - the Prius is environmentally friendly with a SULEV (super ultra low emissions vehicle) rating and the car has some pretty neat technology. The hybrids generally sell better on the Coasts in heavier traffic areas as they do get better mileage in slow stop-and-go traffic compared to high-speed highway driving. Because of the high torque in the electric motor, it has good acceleration and is no slouch on the highway either - I've had it up to about 85 mph very briefly as a test without a problem. When you are stopped, the gas engine totally shuts off and I've been able to run up to about 30 mph in electric mode (Prius owners call it "stealth" mode).

Overall, if your driving it a lot of highway, the hybrid choice would be more for environmental reasons. If it's stop-and-go city, you be ahead in terms of gas costs in a couple of years. (Also drove a Civic hybrid - good car; and my next car may be a Toyota Highlander hybrid SUV.)

BTW: Current dealership wait for a Prius is about six months.

jamestox
2005-Jan-30, 03:12 AM
I think the regenerative breaking is the main reason for the improved (city) fuel efficiency. I think that regular friction brakes are employed for high gee stops which tends to negate the regenerative effect. I believe that you canít get the mileage without changing driving habits.

Our agency has two Prius Hybrids in the fleet, a 2001 and a 2003; when you decide to stop, the mechanical brakes are the first to operate, then the computer commands the regenerative brakes a split-second after the pads start the deceleration, giving a "two-stage" braking sequence. The harder you press the pedal, the greater the regenerative braking.

To date, we can average as high as 47-49 mpg in mixed-condition driving. That sounds impressive until you look at the figures for the new-model VW Jetta gas and diesel cars. The gas versions are very close in mpg performance, with no hybrid system involved, and the diesels exceed that mpg due to new-generation engine control computers (and they run almost as cleanly as the gas versions).

However, the Prius is much heavier than the Echo (the chassis the model was orignally based on), with the "drive" battery in a compartment directly above the rear axle, and handles like a heavier car. Also, you must consider maintenance on two batteries with the Prius: the "drive" battery and the "start" battery.

For all the bells and whistles, the hybrids make sense from the environmental point of view - they produce less pollution, but there are vehicles on the market that can come close in performance, mileage, and they are less complex.

jamestox
2005-Jan-30, 03:19 AM
I doubt it shuts off completely, more likely its put in neutral while the electric engine takes over. Its still idling, which is why you still burn gas at slow speeds while the electric is working, but its probably not doing more than turning the alternator.

It shuts off completely. When you come to a stop for more than a few minutes, the computer kills the gas engine. I've amazed onlookers when the traffic light changes and I start the Prius rolling through the intersection completely silently; at about 8-10 mph, the computer spins the starter and lights off the gas engine again to supplement the acceleration and to start the recharge on the drive battery.

In parking lots, with speeds less than 8 mph, you can cruise around on the electric motor alone - it's like a four-door, Interstate-legal golf cart!

Swift
2005-Jan-30, 04:05 AM
I'll try to cover all the different points people made.

My wife and I (it's 'her' car) own a Honda Civic Hybrid. We have had the car about a year and a half and are very pleased with it. From a purely economic standpoint (Return on Investment) I'm not sure it makes sense, as long as gas stays at $2/gallon or less in the US. I'm not sure at what price the hybrid starts making money. The point about the longer you keep it, the better the payback, is a good point. From a purely economic standpoint, I've read that buying a small 4-cylinder with ~40 mpg probably is a better deal.

At the time we bought the car, there was a tax credit for buying a hybrid, which did cut the "premium" over a regular car by about half. I don't know if that is still in effect.

Regenerative breaking is part of the fuel savings, but it is not the entire picture. One of the other things is that the gasoline engine is run such that it runs closer to a constant RPM, which I gather is a more efficient way to run the engine. If it is generating more power than needed to move the car, the rest goes to charging the battery; if it is not enough, the electric motor helps. The engines are also smaller (I think around 80 horsepower) than you would normally find in a car that size. The loss you have for acceleration is made up for by the electric motor. The Honda, and IIRC the Toyota Prius also use Continuously Variable Transmissions, which also helps a little. Both the Honda and the Prius shutoff the engine for stops and the Prius can actually run at slow speeds just on the electric (the Honda turns on the gasoline engine as soon as you start moving).

I have heard/read comments from people who were disappointed with the fuel economy. Other than a short break-in period, our's has been good. It is a little better in stop-and-go, but we did a trip from Cleveland, OH to the UP of Michigan last year, almost all highway driving, and averaged 50 mpg for the trip.

Cleveland has been below freezing most of the winter. The car runs fine. There might be a loss of a couple of MPGs in cold weather.

There is a the question of battery life. Both Toyota and Honda are giving 100,000 mile warrenties on the batteries. Honda has not set a firm price for a new set, but the people we've talked to say it will probably be like the cost of a transmission rebuild for a regular car. Toyota has actually been selling hybrids in Japan for at least 5 years, and Honda almost that long, so they do have some long term experience with them.

The choice between the Civic and Prius was made purely on style. The Civic is almost identical in appearance to the standard, high-end model Civic, except for no sun roof (I don't know why :-? ). The Prius is a bit 'different' in style, you either like it or you don't.

As I said, my wife and are very pleased. The environmental aspects were certainly part of our decision, so I don't think I could recommend it for pure economics, unless you think gas will be $3 or $4/gallon (which I wouldn't completely rule out). But if you are shelling out about $20k for a new car anyway, it's not all that much more to be greener.

A Thousand Pardons
2005-Jan-30, 01:01 PM
I doubt it shuts off completely, more likely its put in neutral while the electric engine takes over. Its still idling, which is why you still burn gas at slow speeds while the electric is working, but its probably not doing more than turning the alternator.

It shuts off completely. When you come to a stop for more than a few minutes, the computer kills the gas engine.
Doodler was talking about just backing off on the accelerator, not just a complete stop.

The Civic is different from the Prius. But there is a significant gas savings on long highway trips because it has such a small gas engine. But it loses little in the acceleration because of the electric boost.

As battery weight falls, I expect the concept to be used in performance cars, since electric has advantages there.

Togusa
2005-Jan-30, 03:06 PM
To date, we can average as high as 47-49 mpg in mixed-condition driving. That sounds impressive until you look at the figures for the new-model VW Jetta gas and diesel cars. The gas versions are very close in mpg performance, with no hybrid system involved, and the diesels exceed that mpg due to new-generation engine control computers (and they run almost as cleanly as the gas versions).
But not as cleanly as the Prius, which is rated as a PZ-ULEV (Partial Zero-Ultra Low Emission Vehicle) in California, and as an SULEV (Super Ultra Low Emission Vehicle) elsewhere, by the EPA. The Jetta diesel emits much higher levels of particulates and nitrogen oxide -- higher levels than those put out by the gasoline version of the Jetta -- mainly due to the "dirty" high-sulfur diesel fuels widely available in the US. (Of course, this will change when the EPA mandates low-sulfur diesel fuels in 2007 or thereabouts).


However, the Prius is much heavier than the Echo (the chassis the model was orignally based on)[...]
Actually, the only thing the "Classic" (2001-2003) Prius has in common with the Echo is the engine, which, for the Prius, was modified to operate on the more-fuel efficient Atkinson combustion cycle rather than the standard Otto cycle. The Classic Prius' chassis is unique to the Prius.

Of course, the "Hybrid Synergy Drive" Prius (the 2004-2005 model) is completely new.

As for weight, sure, the Prius is heaver than the Echo, but the Prius isn't even in the same vehicle class as the Echo -- the Echo is a subcompact, but the Prius is a mid-size car. Thus, a better comparison would be between the Prius and the Camry (another Toyota mid-size car), in which case the Prius is much lighter (2,890 lb. curb weight vs. the Camry's 3,108 lbs.). (In fact, the larger '04-'05 model is nearly 300 lbs. lighter than the smaller '01-'03 model.)


Also, you must consider maintenance on two batteries with the Prius: the "drive" battery and the "start" battery.
The Prius' nickel-metal hydride drive battery is largely maintenance-free -- the car's vehicle management system ensures that the drive battery is properly charged and conditioned.

Maintenance of the 12-volt accessory/starter battery is no more intensive than the one in a regular car. It only becomes an issue if one uses potentially power-draining options like the Prius' Smart Key System (leaving the system active for long periods of time without driving the car can drain the accessory battery).


For all the bells and whistles, the hybrids make sense from the environmental point of view - they produce less pollution, but there are vehicles on the market that can come close in performance, mileage, and they are less complex.
The Prius' drive system, despite its greater reliance on electronics, is actually less mechanically complex than other vehicles of similar fuel effiency -- the Prius' "transmission" is actually an electronically-controlled planetary gear set; with fewer moving parts than a standard automatic transmission, and no parts that disengage and re-engage, it's far more likely to last the life of the car and require little or no maintenance.

jamestox
2005-Jan-30, 07:57 PM
I doubt it shuts off completely, more likely its put in neutral while the electric engine takes over. Its still idling, which is why you still burn gas at slow speeds while the electric is working, but its probably not doing more than turning the alternator.

It shuts off completely. When you come to a stop for more than a few minutes, the computer kills the gas engine.
Doodler was talking about just backing off on the accelerator, not just a complete stop.

The Civic is different from the Prius. But there is a significant gas savings on long highway trips because it has such a small gas engine. But it loses little in the acceleration because of the electric boost.

As battery weight falls, I expect the concept to be used in performance cars, since electric has advantages there.

In high-speed constant cruise (highway speeds), the Prius doesn't shut down, just runs the gas engine at a speed to balance the charge/discharge rate for the drive battery; if you command a rapid acceleration, both electric and gas motors are used. During long-term deceleration (down a hill), on occasion, the computer will command a shutdown of the gas engine, but most times, it'll just run at idle.

One thing came up during a fuel stop: some firemen were intrigued with the Prius' mechanics, but did ask one very important question. "Is there a master cut-out for the drive battery? If so, where is it?" He was naturally concerned with an accident rescue scenario with a high-amperage electrical source onboard. Wish I could've helped him....I hadn't gotten to that part of the owner's manual yet. :)

Kesh
2005-Jan-30, 08:23 PM
Currently, it's not very cost efficient to buy a hybrid. They cost more than a standard car and, though you do save on gas over the years, eventually the battery needs replaced. And that battery is extremely expensive.

This may not be a concern if you're trading cars every few years, but if you want a long-term vehicle, it's not really going to save a lot of money. Not until the batteries go down in price anyway.

From an environmental standpoint, though, they're pretty nice. :)

jamestox
2005-Jan-30, 09:07 PM
But not as cleanly as the Prius, which is rated as a PZ-ULEV (Partial Zero-Ultra Low Emission Vehicle) in California, and as an SULEV (Super Ultra Low Emission Vehicle) elsewhere, by the EPA. The Jetta diesel emits much higher levels of particulates and nitrogen oxide -- higher levels than those put out by the gasoline version of the Jetta -- mainly due to the "dirty" high-sulfur diesel fuels widely available in the US. (Of course, this will change when the EPA mandates low-sulfur diesel fuels in 2007 or thereabouts).True. The emissions are largely dependent on the fuel, which will change in the near future. Carbon dioxide and water vapor (considered "greenhouse" emissions) are less than the gas version.

However, the Prius is much heavier than the Echo (the chassis the model was orignally based on)[...]Actually, the only thing the "Classic" (2001-2003) Prius has in common with the Echo is the engine, which, for the Prius, was modified to operate on the more-fuel efficient Atkinson combustion cycle rather than the standard Otto cycle. The Classic Prius' chassis is unique to the Prius. The 2001 4-door Echo has a standard wheelbase of 93.3"; the Prius' is 100.4" long, that's only a 7.1 inch difference. The overall length is 163.2" Echo/169.6" Prius - a roughly 6" difference, and that still places both models firmly in the Compact class and with very similar chassis design. I will take your word on the combustion cycle for the engines. However, both use the Toyota 1.5 litre 4-cylinder.
Of course, the "Hybrid Synergy Drive" Prius (the 2004-2005 model) is completely new. As for weight, sure, the Prius is heaver than the Echo, but the Prius isn't even in the same vehicle class as the Echo -- the Echo is a subcompact, but the Prius is a mid-size car. Thus, a better comparison would be between the Prius and the Camry (another Toyota mid-size car), in which case the Prius is much lighter (2,890 lb. curb weight vs. the Camry's 3,108 lbs.). (In fact, the larger '04-'05 model is nearly 300 lbs. lighter than the smaller '01-'03 model.)Weight-wise, the Prius is within 300 lbs of the same weight-class as the Camry. However, size-wise, it is in the Compact class with the Echo, as the interior dimensions are nearly identical in the passenger compartment and baggage area; the wheelbase figures and overall exterior dimensions are very close between the Echo and Prius and these figures are what the automotive industry use to assign size classification. I merely meant to point out that while, size-wise, the Echo and Prius are very close - due to the drive battery - the Prius is a whopping 800 pounds heavier, with essentially the same suspension/chassis design as the Echo. By the way, the 2000 Toyota Corolla (also classed as a Compact) curbs at 2414 pounds, has overall length of 174" and a 97" wheelbase.

Also, you must consider maintenance on two batteries with the Prius: the "drive" battery and the "start" battery.The Prius' nickel-metal hydride drive battery is largely maintenance-free -- the car's vehicle management system ensures that the drive battery is properly charged and conditioned. Maintenance of the 12-volt accessory/starter battery is no more intensive than the one in a regular car. It only becomes an issue if one uses potentially power-draining options like the Prius' Smart Key System (leaving the system active for long periods of time without driving the car can drain the accessory battery). The drive-system battery is warrantied for 100,000 miles, and according to Toyota, "Replacement costs would be comparable to the cost of a transmission rebuild after the warranty period." For me this is serious stuff; my last vehicle ran 254,000 miles before I traded it in on my current ride in 2000....and it now has 154,000 (I bought it with 30,000). Last time I checked, a transmission rebuild ran about $2500, complete with removal and reinstallation. For me, such a vehicle might not be all that practical; for others, it would. As the saying goes, "Your mileage may vary." :)


For all the bells and whistles, the hybrids make sense from the environmental point of view - they produce less pollution, but there are vehicles on the market that can come close in performance, mileage, and they are less complex.
The Prius' drive system, despite its greater reliance on electronics, is actually less mechanically complex than other vehicles of similar fuel effiency -- the Prius' "transmission" is actually an electronically-controlled planetary gear set; with fewer moving parts than a standard automatic transmission, and no parts that disengage and re-engage, it's far more likely to last the life of the car and require little or no maintenance.The term is "constantly variable ratio" transmission and is great stuff, and I hope it can hold together. Designs have been tried in the past and haven't been all that reliable. The concept is very sound and makes for a great method of getting torque and power to the wheels. The "complexity" I mentioned refers to the less-than-simple combination of electric drive components, internal combustion drive components, and computers. Call me old fashioned, but there are very few things the owner can service aside from changing the plugs, oil, coolant, and servicing the start battery. Even when I can't perform the service myself, I consider it an important point of having some idea what's wrong with my car when dealing with the service department. :)

Again, "YMMV." What's important to me may not be to you. That's what makes this a great country! :D

Moose
2005-Jan-30, 09:19 PM
In high-speed constant cruise (highway speeds), the Prius doesn't shut down, just runs the gas engine at a speed to balance the charge/discharge rate for the drive battery; if you command a rapid acceleration, both electric and gas motors are used. During long-term deceleration (down a hill), on occasion, the computer will command a shutdown of the gas engine, but most times, it'll just run at idle.

Hmm. That actually reminds me. Is there a way to generate resistance from the engine rather than be heating up your brakes keeping control down a long hill? It's not much fun to get to the curve at the bottom and your brakes pads have just burnt off.

archman
2005-Jan-30, 09:32 PM
According to Automobile Magazine, the new Toyota Prius is classified as a mid-size car, having "94 cubic feet of passenger space". I guess cubic feet is how car sizes are rated. But this standard must get tweaked from time to time, as "mid-size" cars seem smaller and smaller to me as the years go by.

http://www.automobilemag.com/reviews/sedans/0310_toyota_prius/

There's some other neat stuff about the Prius in the review also, particularly differences between the older "compact" version and the new one.

ChaosInc
2005-Jan-30, 09:55 PM
Swift (amoung others):
The hybrid drive only applies to the front wheels on the Prius and Civic. Does that mean that they have normal friction-type rear brakes? Have you driven much through mountains with one?

lyford
2005-Jan-31, 02:16 AM
I am looking to buy a new car in the coming year. I commute 70 plus miles a day, and my current econobox 1998 Escort wagon averages about 30 mpg. (Livin' Large!) In my opinion, gas in the States will only go up in the next few years, so a better mileage cost benefit will increase. I had my eye on the Honda Element, but they get less mileage than I get now, so now I am interested in the Prius and the new Escape Hybrid. I noticed that some of the car companies are making hybrid versions of their big trucks, but they get 18-20 mpg instead of 8-12 mpg. I guess that's better than nothing!

But I would be mostly interested in knowing more about the emissions and environment side: Do the batteries pose special toxic disposal issues? Are we just replacing air pollution with groundwater pollution? :-k

A Thousand Pardons
2005-Jan-31, 02:55 PM
One thing came up during a fuel stop: some firemen were intrigued with the Prius' mechanics, but did ask one very important question. "Is there a master cut-out for the drive battery? If so, where is it?" He was naturally concerned with an accident rescue scenario with a high-amperage electrical source onboard. Wish I could've helped him....I hadn't gotten to that part of the owner's manual yet. :)
The "big" battery isn't even mentioned in the Civic owner's manual. It's as if it didn't exist--and according to the tech at the dealership, that's the way it's intended. They don't want the backyard mechanic delving into such arcane mysteries.

You can't even find the specs in the owner's manual. The tech manual (available for $70) says it's 144 volt.


Hmm. That actually reminds me. Is there a way to generate resistance from the engine rather than be heating up your brakes keeping control down a long hill? It's not much fun to get to the curve at the bottom and your brakes pads have just burnt off.
You are probably talking about the regenerative braking?

Swift (amoung others):
The hybrid drive only applies to the front wheels on the Prius and Civic. Does that mean that they have normal friction-type rear brakes? Have you driven much through mountains with one?
The Civic has front disc brakes, and rear drum brakes. There is no regenerative braking actuated by the brake pedal.

ToSeek
2005-Jan-31, 02:59 PM
In high-speed constant cruise (highway speeds), the Prius doesn't shut down, just runs the gas engine at a speed to balance the charge/discharge rate for the drive battery; if you command a rapid acceleration, both electric and gas motors are used. During long-term deceleration (down a hill), on occasion, the computer will command a shutdown of the gas engine, but most times, it'll just run at idle.

Hmm. That actually reminds me. Is there a way to generate resistance from the engine rather than be heating up your brakes keeping control down a long hill? It's not much fun to get to the curve at the bottom and your brakes pads have just burnt off.

My wife and I have a Honda Insight with regenerative braking. You can actually watch the battery charge up if you're going down a long hill and having to brake.

Moose
2005-Jan-31, 03:29 PM
I don't mean charging the battery by braking. I mean the hybrid equivalent to downshifting (manual shift) so as to let the engine slow the car, rather than using the brake.

On long, steep mountain roads with tight corners, you really need to be off your brakes as much as possible (for when you _really_ need them), but travelling slow enough to negociate the turns safely. Easing down a mountain in the lower gears makes a big difference in keeping your brakes cool and your pads on the car.

This is mostly an issue in mountain country, but there are more than a few hills in the Maritimes (especially along the Cabot Trail) where this is somewhat of an issue as well.

Swift
2005-Jan-31, 04:05 PM
Swift (amoung others):
The hybrid drive only applies to the front wheels on the Prius and Civic. Does that mean that they have normal friction-type rear brakes? Have you driven much through mountains with one?
A Thousand Pardons covered the mechanical aspect. I've driven the Civic on all the mountains of Ohio :wink: . But seriously, nope, can't say I've driven it in any serious mountains.


I don't mean charging the battery by braking. I mean the hybrid equivalent to downshifting (manual shift) so as to let the engine slow the car, rather than using the brake.
I know your talking about mountain driving Moose, but just to finish up the stuff about charge/discharge...

The engine will charge the battery, even without braking. As ToSeek mentioned, coasting down hill, the battery will charge. On the Civic there is a nice little digital display that shows when you are charging and when you are discharging. I've noticed that even when I lightly accelerate, I will discharge slightly and when I lightly deccelerate (by easing up on the gas pedal) it will charge slightly.

Back to Moose's question, I don't have any particular experience.

A Thousand Pardons
2005-Jan-31, 04:39 PM
I don't mean charging the battery by braking. I mean the hybrid equivalent to downshifting (manual shift) so as to let the engine slow the car, rather than using the brake.
Regenerative braking does not use the brake pads, but regardless you can downshift. Our Civic is a manual transmission but the Continuously Variable Transmission has the familiar PRNDSL positions, too.

jamestox
2005-Jan-31, 05:01 PM
In high-speed constant cruise (highway speeds), the Prius doesn't shut down, just runs the gas engine at a speed to balance the charge/discharge rate for the drive battery; if you command a rapid acceleration, both electric and gas motors are used. During long-term deceleration (down a hill), on occasion, the computer will command a shutdown of the gas engine, but most times, it'll just run at idle.

Hmm. That actually reminds me. Is there a way to generate resistance from the engine rather than be heating up your brakes keeping control down a long hill? It's not much fun to get to the curve at the bottom and your brakes pads have just burnt off.

Yes, there is. The shift lever has a "B" ("brake") position used in the place of the automatic transmission "L" ("low"). It forces the CVT to a lower ratio for dynamic braking down hills. This also increases the ingoing charge to the battery via the motor/generator. Please keep in mind that this is all from driving experience of either a 2001 or 2003 model year Prius, and not from any other model years. :)
There is less heat-related wear on the mechanical brakes, since both the mechanical brakes (disc/drum), AND the regen brakes are being used to slow the vehicle. Ya just gotta go easy on that pedal, because when the regen brake system kicks in, you definitely feel it. The "one-TWO" braking sequence was the most difficult thing for me to come to grips with; smoothly stopping that Prius took practice and a gentle touch.

jamestox
2005-Jan-31, 05:17 PM
... On long, steep mountain roads with tight corners, you really need to be off your brakes as much as possible (for when you _really_ need them), but travelling slow enough to negociate the turns safely. Easing down a mountain in the lower gears makes a big difference in keeping your brakes cool and your pads on the car.

This is mostly an issue in mountain country, but there are more than a few hills in the Maritimes (especially along the Cabot Trail) where this is somewhat of an issue as well.

We have a few mountains (Smoky Mountains, Monteagle) in our area and the Prius' brakes have no problems with them. As I said, you really have to get the feel for the way the mech/regen system engages. Our Priuses ("Priui"?) have handled the downhills well, but that big battery over the rear axle really makes itself felt in the curves. Where the car really shines is in the urban regime - the mileage figures reverse! In stop-and-go stuff, the electric/gas hybrid system nets better gas mileage than driving on the open road. Of course, how you drive it makes a big difference. Sometimes it gets better mileage with me than some of the other drivers in the department (I'm used to driving for good economy behind the wheel of a motorhome - you pull every trick you can for good gas mileage when you pay $1.85/gal...and buy 50-60 gallons at a time).

YMMV.....couldn't be truer.

BTW, my wife and I drove the Cabot a few years ago. BEAUTIFUL country. Really nice people, too.

Moose
2005-Jan-31, 07:06 PM
Huh. Neat. I might see about renting one sometime to get a feel for them.

Kind of moot, though, I'm planning on driving my corolla another 8 years, but if gas/electrics do have hard winter problems, I'm sure they'll have them figured out by then.

geonuc
2009-Feb-08, 12:46 PM
Sorry about the thread necromancy, but this thread is exactly on point for what I want to ask.

I have to buy a car fairly soon. One of my vehicles was recently totalled, and the fleet is down to critical level.

So, given that my wife and I are treehuggers and given that last year a couple of hurricanes knocked out Atlanta's gasoline supply for a number of weeks, we are focused on a high-mileage car. We rented a Toyota Prius for a few days and were quite impressed with the car. However, I know that Toyota has plans to use Lithium ion batteries in the 2011 model year and I'd really like to wait for that, but 2011 is a long ways off.

Options at the moment are:

New Honda Fit
Used Toyota Corolla (the new ones are not good)
New Prius
Used Prius

It's that last one I don't know about. Does it make sense to buy a hybrid that already has significant miles on those batteries? How long do they last, anyway?

Euniculus
2009-Feb-08, 03:33 PM
If you're going to get a hybrid, might as well get a new one or a low mileage used.

I think it was mentioned further up in the thread the batteries are good for around 100,000 miles. Because your wife lives close to work and it's city driving, it would be a better option for her.

Since you commute mega miles to work, you might as well keep your beloved Acura. :D

My treehugging self loves my 98 Corolla, and my husband's 2001 Corolla is holding out pretty well too. Sorry to hear the new ones aren't as good, because I'm looking into a newer car as well.

Swift
2009-Feb-08, 06:15 PM
Since this thread started, I've also purchased a 2005 Ford Escape Hybrid (purchased new June 2005). Both the Escape and my wife's 2003 Civic Hybrid are around the 100,000 mile mark (I'm actually closer to 115,000 - I drive a lot) and the battery packs are fine on both.

I generally buy new, but then I keep my cars a long time (200,000 miles or so). But if you are replacing it in 2 years, I would also go for a used one now. The various hybrids have been around long enough, I'm sure you can find a used one.

There are some big deals on new cars at the moment - I think Toyota is even giving deals on the Prius at the moment.

I don't know the current status of the tax credit for hybrids, but it would only apply for a new one.

geonuc
2009-Feb-08, 10:20 PM
I think it was mentioned further up in the thread the batteries are good for around 100,000 miles.
Yes, but the thread is four years old, and I assume some improvement in the tech has occurred since then.

Swift - we tend to keep cars a long time, too. The truck that just got smashed was twenty years old with over 200K on it and the Civic that died a similar death last year was twelve years old. But I'm thinking a used Corolla now and trade it in on a new 2011 Prius might be the best way to go.

I hate having to shop for cars in a rush. :mad:

Arneb
2009-Feb-08, 10:35 PM
Since this thread was put aside VW/Audi/Mercedes have improved considerably on their Diesel technology, with higher mileage, automatic particulate filter (was about time) and a few other ways to reduce the "dirty" part of those.

I don't know if they have closed the gap to the gas hyprids in terms of emissions completely, but it might be a good idea to have a look into these as well.

Swift
2009-Feb-09, 04:36 AM
I think it was mentioned further up in the thread the batteries are good for around 100,000 miles.
The batteries are warranted for 100,000 miles (at least on Toyota, Honda, and Ford). My take on that is that the auto makers think they are good for at least 100,000 miles. I keep up with the hybrid car info (one good website for this (http://www.hybridcars.com/)) and I've heard very little about battery failure. And the Prius was introduced in Japan in 1997!

I've also heard that if the battery fails, you are not talking about scrapping the car. More like the cost of a transmission rebuild.

hhEb09'1
2009-Feb-09, 06:01 AM
I think the Civic uses an ultra capacitor (spell?) in lieu of batteries. What would be the difference?Missed this, four years ago. :)

The 2004 Honda Civic used 120 metal hydride D cells, en gange, behind the back seat so you couldn't fold it down and stuff in your junk through the trunk.

Gandalf223
2009-Feb-09, 06:47 AM
My wife and I finally got fed up with the piece we had been driving, and recently bought a new Prius. So far, so good (we've got about 700 miles on it and are still learning.)

Longest single trip to date: 100 miles, 50.3 MPG.

Average mileage, mostly in town, is running about 43 or so. The weather has been cold, which causes the engine to run more -- the first thing it does is to start and warm up to some preset temperature, plus it runs periodically when you have the heater turned on -- so we're not surprised. My pre-purchase research taught me to expect poorer mileage in winter just because of these things.

The car is like a big freakin' video game for me. The thing is to see how much of the time you can keep it in stealth mode (engine off and running on 100% electric.) Of course, when the computer decides the traction battery needs to be charged, it's gonna start the engine; no way around it. I've managed to go a couple of miles at a time, even up gentle hills when my foot is especially sensitive.

I stopped worrying about keeping up with the punks and their coffee can mufflers a long time ago, so the performance isn't an issue. It's pretty good when you ask for it, and the sound of the gas engine winding up is startling when you've been driving in near silence for hours or days. Besides, not many of the punks can keep up with my diesel pickup (the yang to the Prius' yin?)

Right now, with sales in the toilet, dealers are offering big incentives even for Priuses, so this is probably a good time to buy one. This summer, when gas prices are back up to $4 or more, you can probably name your own price for the car if you don't like it...

geonuc
2009-Feb-09, 10:13 AM
Since this thread was put aside VW/Audi/Mercedes have improved considerably on their Diesel technology, with higher mileage, automatic particulate filter (was about time) and a few other ways to reduce the "dirty" part of those.

I don't know if they have closed the gap to the gas hyprids in terms of emissions completely, but it might be a good idea to have a look into these as well.
I will - thanks.


I've also heard that if the battery fails, you are not talking about scrapping the car. More like the cost of a transmission rebuild.
That's a good way to look at it.


Right now, with sales in the toilet, dealers are offering big incentives even for Priuses, so this is probably a good time to buy one. This summer, when gas prices are back up to $4 or more, you can probably name your own price for the car if you don't like it...
Another good point, although we hate selling cars before their time. I'm not entirely happy with my 2004 Acura TSX, but I've kept it for five years now.

BTW, welcome to BAUT, Gandalf.

Swift
2009-Feb-09, 03:58 PM
Average mileage, mostly in town, is running about 43 or so. The weather has been cold, which causes the engine to run more -- the first thing it does is to start and warm up to some preset temperature, plus it runs periodically when you have the heater turned on -- so we're not surprised. My pre-purchase research taught me to expect poorer mileage in winter just because of these things.

I have the same thing with my Escape hybrid. My understanding is the cold has two effects. First, all small gas engines do a little worse for MPG in the winter - my RAV4 used to drop from around 25 mpg to 23 in the winter.

Second, like most batteries, the hybrid batteries do not work as well in cold weather.

On my Escape, with my normal mix of driving, I get about 36 to 37 mpg in the summer, and 32 mpg in the winter.

geonuc
2009-May-10, 01:44 PM
Well, we decided to put off the purchase of a hybrid for now. The 2010 Prius looks good (not on sale in Georgia yet), but I understand they're going to lithium batteries soon and we'd rather have that. Couldn't interest my wife in the VW TDI Jetta, even though the gas mileage is outstanding.

So we bought a 2007 Toyota Corolla. It gets better mileage than the new ones and we saved a couple of bucks buying used. If we choose, we can trade that in for a 2011 (or whatever) Prius when the new batteries get here. Or not. The Corolla is bulletproof.

Gandalf223
2009-May-10, 04:32 PM
My wife and I bought a 2009 Prius four months ago. It's an amazing car, and wildly different from anything you've seen before.

The Prius has a fairly small gasoline engine, and two (2) electric motor/generators ("MG".) Either, or both, of the MGs can be operating as a motor, or as a generator. Much of the time, one is in motor mode, while the second is in generator mode.

The Prius has no transmission in the conventional sense. Toyota claims it has a CVT (constantly variable transmission) but in reality what the Prius has isn't like any CVT you've ever seen. The Prius has a planetary gearset, with one MG connected to the sun gear, the other MG to the ring gear and the gas engine connected to the planet gears. It has a chain drive from the planetary gearset to more reduction gearing and then to the drive wheels. It nevers shifts gears.

The driver does not get to choose when the gas engine runs. There is no starter, and you don't turn a key. You push a button to energize the car's computers, and the computers decide when to start the engine. In practice, the engine will always start, about 8 seconds after you turn the car on. The engine will run until it reaches normal operating temperature, then it will start and stop as directed by the computers.

In city driving, below about 40 MPH, it is possible to drive the Prius with the gas engine completely stopped. When you need more power, such as going up a hill or accellerating quickly, the engine will start. Going downhill or on the flat if you have a soft foot, the engine may stop and you'll be back in "golf cart" mode. The engine will also start when the high voltage battery's state of charge is down. Again, you don't get to decide; the car does.

When you drive faster than about 40 MPH, the gasoline engine will always be turning. If it were stopped, MG2 (the one connected to the sun gear) would be forced to spin so fast that it would self destruct. Usually, the gas engine is burning fuel, but there are times when the car will shut off the fuel supply and the GE is simply spinning without running.

The Prius does have two batteries. The high voltage traction battery is a lithium type. Great energy density, but I'm not sure if they're less polluting than lead/acid batteries. It's heavy and expensive, and the early models had to be replaced entirely if a cell failed (at a bit over 200 volts, there are many cells.) The HV battery in the current Prius is entirely modular, so if a cell fails it can be replaced. (NOT by the typical consumer, though; the voltage and available current in the HV battery are LETHAL.) As for reliability, it seems people are getting 200,000 miles from the traction batteries, even in taxi service. If you do have to replace the HV battery it will be very expensive.

The second battery is a lead/acid absorbed glass mat type, about 28 AH capacity so it's much smaller than the lead/acid battery in most cars. It is used to power the computers and accessories, but never to start the engine. Contrary to some popular belief, the 12V battery in the Prius is not used for starting the gas engine. In fact, there isn't a starter motor at all, per se. The gasoline engine, when called for, is started by one of the two HV electric motor/generators, MG2. The Prius draws a small amount of current from the 12v battery at all times, even when parked, so they advise you not to leave the car parked for more than 3 weeks unless you disconnect the 12v battery or put a trickle charger on it.

The air conditioner compressor is electric. It runs from the high voltage system, so you have A/C even when the gas engine is not running.

In four months, we've been averaging about 43 MPG in the city, and 48 to 50 on the highway (47.5 with four adults on board.) We're happy with that. When gas prices get back up to last summer's levels we'll be ecstatic.

As a pure hybrid, the Prius gets 100% of its energy from the gasoline you put into the tank. It does a pretty good job on the highway, but is without equal in the city. So your choice should include factoring in where you do your driving. I've seen some calculations (other people's) that suggest you'll recoup the extra cost of a Prius in about 100,000 miles, so if you trade cars often you won't see much saving if any. If you're among those of us who buy and car and then drive it until the wheels fall off, you should come out ahead.

In the meantime, I'll be thumbing my nose at the oil companies...

Swift
2009-May-10, 05:48 PM
So we bought a 2007 Toyota Corolla. It gets better mileage than the new ones and we saved a couple of bucks buying used. If we choose, we can trade that in for a 2011 (or whatever) Prius when the new batteries get here. Or not. The Corolla is bulletproof.
May you and the Corolla prosper. :D

By 2011 there may be quite a few "whatevers" to look at. The Ford Focus Hybrid just came out and I've read some good reviews. The new Civic Insight Hybrid also just came out - it looks a lot like a cheaper Prius clone.