Yes, but the load change would be constant (for the same car with everything the same except gearing). So when comparing two gears, it wouldn't matter.

Easiest way to "test" the theory. Cruise at 45mph keeping the car in 4th gear, reset fuel economy.

Compare that to cruising at 45mph in 5th gear and the fuel economy. 5th defintely does better at 45mph.

If we had a 6th or 7th, the car should show the same benefit at 70mph+.

yes and no.

6th gear is shorter than the 5th in current 5AT.

5th and current 4th are equal.

7th is the only gear that would improve fuel economy.

This worries me a bit about the tranny then. From what I've heard, trannies with lots of gears (like 7) can have a problem with "hunting" for gears and shifting all the time (which can get quite annoying).

Plus, with 7th only being slightly taller than the current 5th, I don't see how there will be significant gains in fuel economy. With 7 gears, I would've hoped 7th would be a highway only type of gear (like 6th on an LS1 fbody, double overdrive). At redline in my Trans Am, 6th gear would top out over 250mph.

But, it made a 340hp car capable of 28mpg on the highway.

It really depends on the tuning. The MB cars with auto 5 speed doesn't get in the right rear sometime. The Lexus 8 speed auto is flawless.

thanks i was wondering if i was the only one who thought this thread was unnecessary

The point of the post wasn't about the new G37 Sedan. I was told by the dealership in my area that the G35 (current) will be mated w/ the 7speed that will eventually be in the new G37 Sedan that also features VVEL.

Although I actually did realy all 50 pages or whatever, not everyone wants to read through all fluff to get one question answered.