Toyota executives cited two reasons for their choice of nickel-metal hydride.
"It’s a tried-and-true technology that has a decade of success behind it," Toyota spokesman Greg Thome told us. "It's also got the lower-cost technology that we can offer to younger hybrid adopters." The nickel-metal hydride battery pack is located under the rear passenger seat, near the center of the vehicle, and sits low in the chassis to lower the vehicle's center of gravity.
Toyota engineers also made an effort to optimize the motor-generator for the five-door subcompact, Thome said.
"In addition to making the battery smaller, we took special pains to keep the motor-generator smaller, as well," he said. "It's constructed the same as the Prius Liftback's motor-generator, but we tried to optimize the sizing and packaging for a smaller vehicle." The motor's output is 60hp, versus 80hp on earlier Priuses.
The Prius family, unveiled two years ago at the Detroit Auto Show, also includes the Prius Liftback, the Prius v, and the plug-in Prius PHV, which will be introduced this year.
For a deep look at GM's Chevy Volt, we recommend you go to the Drive for Innovation site and follow the cross-country journey of EE Life editorial director Brian Fuller. In the trip, sponsored by Avnet Express, Fuller is taking the fire-engine-red Volt to innovation hubs across America, interviewing engineers, entrepreneurs, innovators, and students as he blogs his way across the country.
Fore efficient AWD, look at the latest Subaru. They made a bold move with the Impreza. Instead of using direct injection engine technology to increase hp like everyone does, they made it more efficient. City is around 25 and highway is about 35. That is almost as good as my Yaris!
All-wheel drive comes at a cost in efficiency - you have to carry the weight of the additional transmission parts. Yes, you can avoid the transmission parts if you go for an electric drive train, but then you have to carry the large battery.
The Toyota Prius Hybrid Synergy Drive is a marvelous design, which is very much misunderstood. It is in no way an electric drivetrain. The electric part of the system serves two purposes:
1) as storage for energy harvested during "braking"
2) as a power assist when accellerating (particularly from a dead stop)
The power assist available from the electric side allows for a much smaller gasoline engine than would normally be required for a vehicle of this size. This saves weight, and it allows the engine to be operate closer to its optimal efficiency during a much larger part of driving than it otherwise could.
Since the battery is not used for extended periods of energy supply, it does not need to be large at all; this saves weight and cost compared with an electric or plug-in vehicle.
The major factors of the Prius' great efficiency are:
- light weight body
- light weight engine
- light weight battery
- recovery of kinetic energy from "braking" in city (start/stop) traffic and congested highway conditions
- continuously variable automatic transmission
Most of these factors are also available to designers of small vehicles with conventional drive trains. For an example look to the Hyundai Elantra.
I am impressed that Toyota can bring this system to a vehicle below $20K, and I think this will further cement Toyota's leadership in the "green" car market.
I am a current owner of a used Camry Hybrid. It cost the same as the non hybrid..used due to market conditions in SO cal at the mie. I have put 22K miles on it. I average 35 with about 31 city and 38 highway mpg. I have rented several camrys of the 4 cyl type of the same body release. series. I have had these in seattle , washington DC, and Detrriot michigan where i ran several tanks on each car in similar driving patterns.
The non hybrid 4 cyl automatics averaged 25 to 28 mpg depending on conditions. This in itself is afavorable to my 96 honda accord wagon whic delivered about the same mpg BUT with a stick and a smaller car and non refomulated fuel which has a siignificantly lower BTU rating.
The differance in cost of a current camry hybrid vs a similarlyconfigured camry is about 3500 HOWEVER the hybrid has several upgrades...a CVT and better GPS sytem and a better stereo which in other cars would sum t 1500 of that delta.
Using the real world numbers on fuel comsumption only with NO consideration for the differance in content....(note the hybrid has SIGNIFICANTLY better performance.)... the pay back at $4 per gallon is...$34 per 1000 mile on FUEL only....there is a reduction in maintenance by reviewing oil condition but i will ignore that. THEREFORE at 3500 price delta the "payback is about 100K miles. HOWEVER the significant perfomance diferance would make the 6 cyl a better comparison NOT for quarter mile but surely for passing. also with the significan content delta which should be talken into account the payback is significanly faster. AS for l;ifecycle costs..record show the batterpacks last about as long as engines...If you run the car that far the replacement is not meaningful.
@Ann: The Prius C is 157" long, compared to 175" for a standard Prius. The Yaris, which is Toyota's subcompact, is 148" long. For comparison, a Chevrolet Aveo hatchback is 159" long, a Mini Cooper is 146" long, a Geo Metro and a Ford Festiva are both 141" long, and a Tata Nano is 122" long.
So the Prius C would probably be considered to be a subcompact, but it's a lot bigger than some of the subcompacts you may be thinking of.
Good points, Naperlou. I guess whenever you look at the environmental impact of a product, you have to look across the lifecycle of the product. You're right, gasoline has a complicated lifecycle from oil to pump.
Thanks for the feedback and answers, Rob. I was betting that the $19K price tag would make a difference in those comparisons. And I agree with you on the importance of electricity production issues, AFA evaluating and comparing the sources and the environmental consequences of that source and its production methods.
Unfortunately we, up here in New England, tend to be ignored when it comes to our expensive energy budgets. With little available sunlight and with heavily forested homesites and hilly terrain our home heating budgets are either satisfied with highly polluting wood fires or expensive oil.
Similarly, no auto makers provide four wheel drive products with anywhere near the fuel economy needed for this region. The choices are gas guzzling SUV's or AWD Subaru's which do better but are still not economical. When will Toyota or others offer an economical AWD hybrid? I'm not going to hold my breath.
There are a lot of Prius's on the road here as we have a lot of environmentally conscious folks in these parts. But you won't see many of them driving their hybrids in stormy winter weather. Toyota's hybrid 4WD offerings start at prices 33% higher than the Prius but with very poor gas mileage. The non hybrid line of 4WD Subaru's do far better but there isn't much more you can squeeze out of their best ICE designs which now sport continuous variable ratio transmissions without gear shifting or energy robbing torque converters.
Borrowing from railroad locomotive technology it should be a no brainer to build a continuous all wheel drive hybrid or all electric vehicle with full time skid and stability control by incorporating direct drive electric motors behind each wheel. Run the ICM engine at its most efficent RPM's all the time when power is required from it to keep the batteries charged and let the electric motor controller do all of the torque assignments as required of the road conditions.
The weight of the additional electic motors could be counterbalanced by the removal of the mechanical transmission. Make it standard technology for all vehicles across a major product line (Subaru for example) and the cost of manufacture will decrease significantly while the vehicle will benefit from improved handling charcteristics during hazardous road conditions.
Wow, that's a long wait, Chuck. Yet I would guess that issue changes as prices for hybrids come down. If hybrids don't cost that much more, the concept of what it takes to make up the differential goes away.
Ann R Thryft; The earlier Prius's were more expensive, but partly because of options. My wife considered the Prius years ago, but could not justify the Nav system, 9 speaker audio, 6-CD changer, &c, &c, We bought a 2010 Prius because it didn't have these extraneous options, and thus was less expensive.
My hybrid Aspen on the other hand, was only built fully decked-out. It is a 2009, bought 1 year ago used, with a 5.7 Hemi V8, and if I pay attention to my driving, and in warm weather, I can average 22 mpg. If traffic conditions are excellent, I can average 26 mpg. The Prius can get 55 mpg, but it can't haul cargo, or tow my trailer.
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