Stock bolton 94 Lt1 with 4.10s i usually get around 25-26mpg on hwy. City we all know how bad they are but who cares really or we wouldnt be on this forum right?

 

13-20 with my mods. Its running a little fat.

 

Then dont jump to conclusions that I didnt use the search option.

Cheer up I have a sense of humor.

 

before I touched the internals I got 32mpg highway

 

I think its tough to judge MPG with a car you beat the **** out of every time you get into it. I get between 150-350 miles per tank.

 

I don't understand how you all get such good fuel mileage. Right now my car is a 93 with an LT4 conversion kit, shorty headers, bigger TB, 3.73 gears, M6. Around city the most i've gotten on my trip meter on a tank of gas 15 gallons mind you, is 240. This number is also inflated because of the 3.73s by about 25%. On the highway, before the LT4 conversion kit i got 280 miles and was on fumes. Best fuel mileage on the highway was about 24.5mpg and this was a 125 mile trip at 50-55mph (1500-1700 rpms in 6th). I've always ran 93 octane fuel in my car. The worst fuel mileage i got was when i did the LT4 conversion, lost some fuel getting it working properly and got a total of 80 miles on the trip meter before i noticed the gauge was sitting at 1/8 of a tank. So my fuel mileage ranges from 4mpg to 24.5mpg.

 

Have you tuned the car since the top end??
Have you tuned up the car? (plus, wires, opti, filters, etc)

 

Yes, since I got the top end done I got it professionally tuned by some guy named Jeremy in St. Petersburg FL. The plugs and wires were replaced. As a matter of fact the PCM went out on the dyno and I had to get a new computer for the car. I'm not sure why I get such horrible fuel mileage, but it isn't really stock either. The previous owner I got it from said it got about 13mpg around the city before the top end was put on. Even with my speedo reporting about 25% high i've never seen my trip meter go beyond 280 miles.