Is it logical that a 2003 miata with a six speed trans and a final drive ratio of 3.10:1 will get the best mileage, since the 2004's went to a final drive ratio of 4.10:1 ?

 

Not necessarily...to assume that lowest engine rpm equals best mileage is too simplified. The engine will have a sweet spot, where you get the most horsepower per gallon consumed. With engine rpm too low, you may lug the engine, which would not be optimum mpg, and also when lugging you do not get throttle response (kinda by definition), and therefore end up downshifting anyway. Perhaps Mazda went to 4.10 to better address that sweet spot, and in fact it may get better mileage than the 3.10.

I don't know specifics to the Miata drivetrain or tire setup, but I'm speaking more in generalities.


Mark in MA

 

Mark, thanks for the response and I agree with your comments. When I first started looking at Miatas, I thought that sixth gear would be like an overdrive gear mainly for the highway, but I've read that the MPG on the highway is about the same with 5 or 6 gears. I was looking for the best combination for highway mileage.

Phil