I have 6 MT o5 sedan 1500 miles. I have done repeatedly 24-25 MPG with:
75% freeway
25% city
Try to shift at around 2500 RPM. Accelerate smoothly
A few times I push the car.
I think once the breaking-in completes I will improve MPG by 2.
i am pleased with th gas mileagee of the G.
Enjoy

 

I am getting around 22-24mpg on my 6mt, granted I am taking it somewhat easy on it right now because its brand new, but still I dont think it will go under 20 when I break it in. I drive about 75% highway 25% city. This is one awesome thing about the manual as I was getting around 17-18 on my 5at.

 

I've been getting 23-24 mpg on my 04 Coupe with combined street/highway driving with the OEM Michelins. Just changed over to the Avon m550s and am still getting consistent 23 mpg. On straight highway driving with cruise, no problems getting 26 mpg. The mileage when the coupe was new averaged around 19 mpg so I'm happy that the engine is finally breaking in.

 

Z tube deffinetly boosted my gas mileage by a slight bit, but any increases are much appriciated, expecially these days.

I drive my G pretty hard, and I usually average 19.5MPG. Mostly interstate highway driving, anything over 23MPG is possible. As long as you aren't beating the hell out your car, servicing the air filter when needed, and keeping your tires inflated (35psi here) you should be good.

Underinflated tires can significantly decrease gas mileage, allthough yeild a softer ride. Overinflated tires can significantly increase gas mileage, allthough yeild a rougher ride (allthough stiffer sidewalls can increase cornering stability) - I find 35/36 psi a happy medium.

 

Did anyone ever swap a AT dif into a 6MT to get a taller gear? That should help. Ya it would slow acceleration down a tiny bit, but just boost it. I think a TT setup with some 2.87s would be perfect.

 

heeb - just the Z-tube by itself netted you a gas milage gain? Interesting, I might have to grab one just to try it out.