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Old 03-30-2014, 06:05 PM   #26 (permalink)
serialk11r
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Quote:
Originally Posted by cRiPpLe_rOoStEr View Post
I also consider the CVT a good option, but finding one suitable to a high torque load is not so easy.
Also transmission efficiency...mechanical CVTs have pretty big losses. I love how CVT cars drive though, no surprise shifts, put your foot down and it goes to the optimum rpm instantly.

I don't understand why some people here don't like more gears. I think 7 is the perfect number, more than that is a little strange. On a Yaris/Fit you have extremely wide spacing for 5 gears, but the cruising rpm is unacceptable and taking off in 1st would be horrendously difficult on a hill if you were to decrease the final drive ratio 20%. With 6 gears and a small engine you can get a good cruising rpm, but engines over 2.4L you would want another gear as can be seen with 6 speed Accords and such.

The 2.7L Porsche 9A1 engines connected to a PDK can get over 40mpg cruising in 7th gear at 65mph, where the engine is only spinning at 1850rpm. Gears 1-6 are like an older "sport" transmission in terms of gearing range except you have 6 speeds instead of 5. If you were to do this with 6 speeds keeping the cruise gear you would have an extra 2 big rpm drops between gears which is unpleasant if you're driving stick.
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