Quote:
Originally Posted by Dadhawk
Yes, I realize it sorta works, but I have to wonder what the fuel mileage of the Prius would have been with just a straight fuel efficient gas engine with the same level (or lack of) power. A lot of the mileage is really in the aerodynamics anyway.
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Nah, the reason it gets such high fuel economy is all in the power split transmission. The engine itself improves peak efficiency over most engines by like 5%, but the transmission gives them the flexibility to run the engine at barely above 1000 rpm all day, and the electric motors do a lot of the work at low speed, so it really lets the engine run at very high levels of efficiency compared to your typical car.
If you want to look at what a fuel efficient gas engine only car looks like, take a look at the Yaris or Fit. They are geared a bit short, and have better acceleration than the Prius, so if they got some mild Atkinson cycle cams and slightly longer gearing, it would be pretty comparable to a Prius as far as performance goes. With even longer gearing and supercharging, you could probably match the Prius' highway consumption.
Around the city though, the regenerative braking and mostly electric power helps the mileage a ton. How much it exactly helps though, I'm not sure. I read that the power conversion efficiency from wheel to battery back to wheel is below 50%, because the mechanical losses and battery losses are quite high, even if the motors and electronics are efficient. Something interesting to try out might be swapping the CRZ drivetrain into an MR-S, I think the significant weight reduction over a Prius might negate a lot of the strong hybrid regen braking advantage.