Hybrids

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varies a lot with how the car is used. A Civic hybrid gets only slightly better fuel economy at freeway speeds than a conventional Civic, and that is only because the engine was downsized when hybridizing the car. The electric assist is intended to make up the difference in acceleration, but there are varying opinions how well that works for the Civic.
Much of the disappointment comes from design considerations. Honda wanted to compete in fuel economy, and to get the very best economy they started with a base model that did well to start with. They could have taken the other path, economical power, as they did with their DualNote concept car... but I'm sure cost would have popped up on that adventure!
Mike
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Michael Pardee wrote:

The problem as I see it is that hybrids flunk the basic keep it simple principle. They have far more components than their conventional counterparts and weigh more as well. More complexity and more weight. Not good general starting point to achieve better efficiency.
Many of the hybrid vehicles are also using other tricks to get some of the fuel economy, which tricks do not require the hybrid powertrain. Smaller engines as you mentioned are one trick. Narrow, high pressure tires are another trick. Cylinder deactivation is another (as used on the V-6 hybrid Accord).
Marketing and hype are clouding many of the facts.
John
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Smaller engines are not a trick but a consequence of hybridization. One of the driving philosophies of hybridization is that it is ludicrous to use a 240 hp engine to move a 5 passenger car around town. Hybrid powertrains make it practical to downsize the engine, since the limiting factor then is the power required for freeway hill climbing - the electrics determine the acceleration performance. Again, I'll grant the current crop of hybrids don't go very far in fulfilling that promise but even the older Prius (like mine) is far more responsive in town than the 75 hp engine would suggest.
No modern car "keeps it simple" but you might consider the tradeoff. The Prius powertrain is complex in concept but not in practice. Actually, any automatic transmission is vastly more complex than the hybrid transaxle. Honda autoboxes are a good example. They have a controller; the hybrid system has a controller. The hybrid system has an inverter; the Honda does not. The hybrid transaxle has a fixed planetary power split device and two motor/generators; the Honda box has an automatic transaxle with lockup torque converter, multiple gear sets, pumps, valves, solenoids, and clutches. The Toyota hybrid system has a main battery, a 12V aux battery and a voltage converter; the Honda has a starter, alternator, regulator, and belts. If the Toyota hybrid has cruise control there are switches; if the Honda has cruise control there is a cruise control module, switches and vacuum motor.
Reliability has seemed to favor the Toyota hybrid system over conventional systems in several areas. There are two known cases of hybrid transaxle failure and unconfirmed rumors of as many as 3 more among the 11000+ members in the Yahoo Prius group over the past 4 years; compare that to the number of automatic transmission problems that show up here. The same Yahoo Prius group has frequent complaints about failure of the undersized 12 volt aux battery, comparable to the number of complaints here about alternator problems (but a whole lot easier to fix). There are a modest number of starter questions here (like "why did my aftermarket rebuilt starter fail the next week" and "how do I get the darned thing out") while the Toyota system has no starter.
Mike
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Yes - I've had it back to the dealer twice - computer showed no problem - the second time the service manager asked me "well, just what mileage would you expect anyway?" I told him I didn't expect 48 but thought low 40s should be expected. He had no answer to that - as far as how the car is driven, when it says 48 city, most people would assume normal around the town driving would do. I did get 40 on a 2000 mile round trip on the interstate last summer, just to see what it would do - of course we don't usually take the civic on long trips, so that figure is pretty redundant.
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muzz wrote:

Dissapointing to say the least.... :-(

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Hello, I read an article about Hybrid vehicles in a car magazine. The magazine staff used a Hybrid vehicle for about two years. Each of the staff members that used the car (for free) for trips had to write a report related to problems and miles per gallon. The consensus was that gas mileage was great when the trip involved lots of city (aka stop and go) driving but was very poor when the trip involved lots of freeway and interstate driving. The reporter that wrote the story indicated that the electric engine kicks in quite a lot in low speed stop and go driving but rarely kicks in on interstate and freeway driving. It was his opinion that this was the reason for the differences in the miles per gallon. The conclusion: If you plan to do a lot of city driving--buy a hybrid. If you plan to use the vehicle for lots of freeway and interstate driving--don't buy a hybrid.
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snipped-for-privacy@nospam.com (Jason) wrote:

Which kind? The series hybrid type such as what Honda does, or the incredibly complex parallel hybrid type such as what Toyota does (and licenses to Ford)?

If you understand what a hybrid does, and what problem it's trying to solve, this is no surprise at all.
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(Jason) wrote:

Exactly. In theory, a serial hybrid could be made with a very low power engine and using just the electric storage for acceleration, and in that way get a measurable improvement in freeway economy. But for the forseeable future hybrids just don't have a significant advantage at freeway speeds. Cars like the Civic are pretty efficient at that already and there is little room for improvement.
Mike
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Yes, I agree that it's no surprise at all for those of us that truly understand Hybrid vehicles. However, the vast majority of people that buy or plan to buy Hybrid vehicles do NOT understand Hybrid vehicles. I've see at least a dozen posts in this and other car related newsgroups from Hybrid owners that were shocked when their miles per gallon were much less than they expected it to be. In almost all of these cases, those people were making use of their Hybrid cars to do lots of freeway and interstate driving. It's obvious that the salesmen that sold them the Hybrid cars did NOT tell them about these factors. My memory is not perfect but I seem to recall that the car mentioned in the above post was a Toyota Prius.
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The main advantage a hybrid has is it's ability to recapture some of the energy which would otherwise be lost to heat by conventional braking. On the open road this is a non-issue.
The second potential advantage of a hybrid is that the gasoline powered engine can be shut down when the car is stopped and the stored energy in the batteries can be used to keep the A/C, radio and other systems alive.
The biggest disadvantage a hybrid has is that it is heavier than the same vehicle without the added batteries and electics. The work done in moving and object from one point to another is a function of the distance and the weights (ok, mass). All other things being equal, a heavier vehicle gets lower fuel economy than a lighter one.
Oddly enough, GM may have the idea more "right" in their limited production pickup truck hybrid system where the electrics are small and light and really only have anough capacity to enable the shut down of the gasoline engine at a dead stop.
John
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L Alpert wrote:

Count me as a hybrid skeptic right now. Most people seem to be reporting real world fuel economy much lower than the EPA published numbers.
Long term running costs including battery replacements, controller problems, etc. are all still to be seen.
Fuel economy wise, diesel engines make vastly more sense than do complex hybrid powertrains.
John
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Here in Tucson, we've had good mileage with our Civic Hybrid. In cool-season city driving, we really do get 45-48 miles per gallon (those are our calculations--the car's computer display inflates mileage by about 3 mpg), with the CVT. In summer, we probably lose about 3 miles per gallon, thanks to the A/C, and whether we have to force the engine to run to keep the cool air blowing at traffic lights (when it's 110 degrees outside).
Freeway driving gives around 36-42--speed limit is 75; real-world practice is closer to 80. Mileage is somewhat better on two-lane roads where the limit is 65. I've noticed a bigger hit on this car from using A/C than on other cars we've had. I'm not complaining; the vast majority of our driving is city driving, and that is this car's strength. It's very enjoyable to get close to 600 miles on a tank of gas.
David
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