I did a mileage check and found that with 50% city and 50% highway, I'm averaging 20.1 mpg.

Engine/drivetrain is mostly in the signature with the addition of a 3.42 axle ratio and a 1996 Corvette lock-up torque converter.

How does that compare to what you guys are getting?

 

With 130,000 on the clock, and I drive hard:

15.5mpg is a good tank. I drive a combo of city and highway.

 

I don't have the TPI done, but I am going for a good 25 or so on the highway, about 19 in the city.

oh, and with 15.5, something is wrong.

 

heh, i drive hard to.. i think somewhere in 16-17mpg city/highway

 

I get 20 to 21 mpg going 75+ on the highway. I usually never check mileage except on long drives. But in town I have a pretty heavy foot.

 

ok guys, Im sad. Gas is killing me.

Im at 12.4 miles to the gallon. ANd thats not shifting above 1700rpms. *** it sucks, why does my car drink gas?

 

Well I'm right at the bottom with some of you other guys. I have checked my mileage on long trips, all highway driving, between 75-80 all the time, and I get about 19-20 miles per gallon. With a mix of Highway and city, roughly 50/50... I get about 15-16 at the best... so that leads me to believe my mileage around town is pretty low, in the 12-14 range.

I do have 176,xxx miles on the clock... 3.08 rear end, and an 700r4 tranny, I do drive pretty hard all the time, but even taking it easier on it doesn't matter... Like how I take it easy when it rains, light on the throttle ALL THE TIME!

Something is wrong, I'm hoping when I put my headers on and get my new y-pipe, and cat delete I will pick up some mileage. We'll see.

 

Eh? Well... sure something is wrong, and I'll find it eventually. When I first got the car I brought it from 11mpg to 13mpg with a tune up. Cleaned the fuel system out with Redline Si2, that brought it from 13mpg to 15mpg. I am thinking my cats are junked, and some exhaust work will go far for me concerning MPG like mentioned earlier.

I have 3.23s... not exactly a low gear. I drive hard tho... and my friend with a 3.4 liter Alero (bunch of mods) gets only about 18mpg. I'm not sweatin it.

 

Regular in town driving, which includes 2 miles to work and back. 5 stop signs and 2 stop lights averages me about 8-9mpg.(talk about stop and go, lol)

Highway 23 mph all day....

When my '86 had 2.73s it would knock down 21mpg at 70mph with that big cam... I have since swapped 3.73s and that pulled it to 18mpg.... Then again I swapped 4.56's but havent gotten a reading yet.

 

Mods in sig, all city so far and I get ~7mpg. I need tuning bad.

*Orders equipment*

 

I don't think there's anything wrong with that. Heavy footed in-town driving mixed with highway miles and 15-16 mpg is exactly what I would expect.

 

I get 22.5 Mpg in my 87 iroc-z with a 350 tpi, stock tranny, 3.23's and mods, my 89 formula 350 got 22.5 to 23.5 depending on how I drove it, I still have to put my plus 4 plugs in my iroc from my formula though.

site check my beasts out.

http://www.cardomain.com/id/cronsformula

 

Around 17.5 - 19 MPG average. I'm on the freeway most of the day averaging around 140 miles per day in my '91 350 TPI.

Don't the 4th Gen LS1's get something around 29 - 30 MPG on the highway?? Makes me wanna get one.

 

We can get amazing highway mileage too, it requires a custom prom - I don't know much about it, but I think the DIY Prom guys would

 

Why get a whole new car when you could just get the 6 speed??

 

the 6 speed helps, but their entire system is a lot better for fuel economy

 

Im sure they have a lot newer everything, newer technologies.....

The ones with automatics only get 25mpg though. It cant be that much better(for gas mileage) because our cars with the same trans gets 23mpg typically.

Im sure dumping a 6 speed in a L98 car could net you 25-28mpg easy enough. Unless theyre looking for an excuse to buy a new car.....just remember 1/2 the motor is under the dash on those cars

 

I am getting right at 19-22 depending on how much city and highway travel I do. On a straight highway run i get 22-23 w/ the 3.42s. Mods are in the sig.

 

don't forget the LS1s put out a good 350hp, versus the power in our comparitively puny L98s

 

Last time I calculated mine I got about 17-18 MPG cruising around town. Now I have my cleaned/fixed injectors to install that don't leak

 

Just curious for the guys getting ~20 mpgs, how long do you run the car before you fill up again? (To the red line)

As for me, I am currently getting about 15mpgs assuming I have a 15 gallon gas tank.