I calculated the mpg on my 84 trans am (l69, 700r-4, 3.73's, 110k) for what was mainly city driving and i stayed off it most the time, my gas milage is 18.1 mpg and the car needs a tune up (its missing). The car has been babied and very well maintained but does this seem high to anyone else?

 

You're complaining because gas mileage is too high??? Sounds about right to me....

Patrick DeGrosse Jr.

 

I'd say that's good. That's about what my 228K, LG4, 2.XX rear nothing rebuilt '86 Z28 gets. It gets around 27 hwy.

 

My brother's high-mile but runs-great LG-4 305 gets about 25 on the highway. Only thing that helps out the mileage is a bump in initial timing of about 4* and an MSD box. He also averages about 18 in mixed city/highway driving if he stays out of it. He's even got the steeper 3.23 gears in back.

 

But this guy's got 3.73s in his!

I don't know how you do that with such steep gearing.