Yaris sales hit new low...

[bronsin]

Originally Posted by nookandcrannycar

I was going by a general assumption that the set up on a 6-speed vs a 5-speed (on average) would allow the 6-speed to be at a lower rpm (and likely higher MPG) than the 5-speed at the same MPH.

If one wound through the gears ALWAYS at a low rpm (trying to get to 5th or 6th as quickly as possible without 'bogging'), wouldn't the diminished efficiency of more gears to 'row'/'wind' through be minimal, or almost non existent ?

In most six speed transmissions the highest speed is equal to or lower than the comparable highest speed in a five speed, four speed etc.

It is unusual for it to be higher which would result in lower rpms.

If you accelerated the engine to the same rpm in a six, five, and four speed transmission before shifting up you would have slightly less mpg the more speeds you shifted through. More speeds does NOT mean more mpg. The eight speed autos Chrysler and others have come out with are just pulling the wool over the eyes of the unwary consumer.

However as you suggest the difference might not be much or even noticeable in practical experience.

And a three speed transmission would not be as adaptable to varying road conditions as a six, five, or even four speed.

HOWEVER!

Manufacturers are guilty of misleading the public in many things. All the time they were increasing the size, weight, and displacement of cars like the Corolla they said "And the mileage is improved!"

Not so.

My sister in law had something like an 85 Camry that got 38 mpg around town while my wifes 05 Camry gets 22.

If you have your heart set on a six speed (soon to be SEVEN speed!) before purchasing get a print out of the final drive ratio of each speed and compare it to the five speed. In many case there IS no five speed to compare it to!

BUT you can always SKIP gears as I did on my motorcycles when going cross country or commuting to work. I shifted my ST1100 and 1300 1-3-5.