Gas mileage: 27 hwy @ 75-80mph / 18-20 city
Horsepower/Torque: 305 rwhp 323 torque
Gearing: 4.10
Transmission: M6
Approx $$ spent on mods: $3000 US
Some mods were on the car already. These #'s are before the hotcam. Stock tune with the hotcam got me 25 hwy / 15-17 city. Dyno tune after LT's should help get the mpg close to what it was before.

 

With a smallish cam (TR220) and nearly full bolt-ons my car's high is 28.4 mpg (sixth gear highway), and a low of 5.7 mpg (on a road course). Details can be found at:
http://chuckb.1le.net/01_trans_am/gas_mileage.html

With just typical minor bolt-ons, it got 29.9 mpg on one leg of a highway trip.

 

20+ city
28+ hwy

 

Gas mileage: 29-30 hwy / 18-19 city
Horsepower/Torque: 315 rwhp / 335 torque
Gearing: 3.42
Transmission: T-56
Approx $$ spent on mods: $85 (lid)

This car has ran many sub-13 sec passes... and it never gets less than 20 mpg combined. My '95 Formula got about 18 mpg driving the same routes.

 

 

My ls1 gets way better then my old lt1.

 

Any more know their gas mileage?

 

00 A4 Z28 w/50K miles. Stock hp and tq. numbers in sig. Not dynoed since mods. Dollars spent to date: ~$120.00

Just filled up this morning and got 23+mpg. That's driving solely my 60-mile per day commute. You could say 70% of that is hwy and 30% is city/stop-n-go-type traffic.

On my road trip to the west coast earlier this year, I got about 26-27mpg on highway driving.

TS

 

Gas mileage: 28-30 on 86 & 87 octane hwy / ~22+ city (depends on how I've been driving)
Horsepower/Torque: unknown, stock w/ muffler.
Gearing: 3.42
Transmission:M6

 

Gas mileage 20 tops usually 18. With light driveing. i use 5th gear religiously.Not too impressive, my old carbed 355 got better mpg than this car. I drive 100% city/town. Gears 342 6spd manual. Oh, and fyi there are no 5spd ls-1's. Money spent on mods...none. HP/Factory Camaro has 63k miles on it.

 

I haven't calculated it exaclty, but I did some stuff to the car (not mods) and it helped A LOT!
before: ~ 200 mi/ tank average
after: ~ 270 mi/ tank average

 

You don't get knocks with 87 octane? That was one thing I was a little worried about with going to an LS1, yea mileage is the same or better then the 6 but I'd have to spend 20 cents more per gallon for premium.

 

Not to hijack this thread but how many miles on average do you guys get from a tank of gas? I'm not worried about mpg or city vs hwy, when you go fill up an almost empty tank, how many miles are on the tripometer? I just bought my 01 Z and seemed to go through the first tank rather quickly. They filled it up for me before I picked it up. I put around 260-270 miles on it and the tank was on E. I don't know if it had premium in it but the manual calls for it so that is what it will get every fill up. It seems more peppy after filling with 92 but that could just be head playing tricks.

 

I get approximately 240 miles to a tank. I think your 260-270 is rather good. Unless your tank is bine dry, you are averaging about 20 mpg.

I usually drive conservatively. I guess my mileage is less than yours because I have to wait in traffic about 15 minutes each morning to get to work.

 

WOW, 270!!! I get 200 if i am lucky and thats as i said with a feather foot and 5th gear whenever i go above 40mph.......something must be wrong with my car