First off let me say I am missing about 10 receipts, all in-town, which would pull the average down since the road trip receipts are included.

That out of the way, for the 39 receipts I have, the green Z28 has averaged just over 22mpg, thats right, twenty two. The high is 30.4 (all interstate), low 16.2 (hot rodding it with a/c blasting). For the most part I don't beat on it, but frequently accelerate quickly (shift point <= 4k).

As for the missing receipts, assuming the car averaged 20mpg for those 3000 miles (300 per fillup), which gets the odometer very close, it still has close to 21.6mpg. Not bad for a pushrod dinosaur. Only mods are a "lid" and Nitto drag radials. It has 96k miles.

I used to get 30 mpg on the highway stock and 16 in the city. After headers, my mileage went down significantly. With tuning I was able to get some of that back on the highway and do better then stock in the city. Now I get about 18mpg city and there is not enough non-traffic highway around DC to get accurate highway mileage.

I get low-to-mid 20s from our 92 B4C w/305/5sp. I'm quite happy with that. Fun car to drive, and mileage to boot. Barbara's 95 Z28 'vert with the monster motor has membership to the Friends Of OPEC Club membership at 16 mpg when she tries.

Getting low 20's combined with the beast 305 with LT1 cam. My DD Saturn Vue Green Line (almost hybrid) get's ~30 mpg combined, not bad for an SUV!

I'm with Gene on this one.

I'll get a solid 20 to 21 driving Miss (92 5.0tpi/5sp/3.42) like a 16 year old idiot every day (30% highway, 70% freeway, 100% driveitlikeyoustoleitandwatchforcops) and easily pull over 25 when traveling. My best is 28.x on the way to an autocross in College Station (I live 160 miles from there) but I was drafting Nick (txagz28) in his z28 and tire trailer.

Costas

I got about 28 MPG on my last road trip with my stock 1998 M6 Z28, all interstate driving, some hills. I had Mac's awhile ago, but had to change back to the stock exhaust manifolds for the SMOG test.

I did notice that Mac's decreased my mileage( never had money for a tune) on the stock tune, but I always thought that a tune could bring ALL the mileage back as long as I was light on the gas pedal (interstate driving at 75MPH ONLY!). I guess when you increase power, you have to use more fuel, no matter if the gas flow in and out of the combustion chamber has increased.

Anyway, I wish I could keep my Mac's on my car all the time and not have to change headers->manifolds every 2 years.... Damn Kalifornia!! Nicest Weather in the US, crappiest laws in the US!

ususally 17-19 in my 5.7 TPI auto 3.42. I got 22 once with only freeway driving; pretty much cruise control @ 70-75 mph for 160 miles. Stock cam with exhaust and intake mods. Part throttle VE not tuned.
I've gotten O2 sensor codes, probably b/c the part throttle VE is off.

My best story is returning from NC to Florida after tuning (96, LT1, 383, 440+hp) I got 25 mpg on the highway

That was cruise controlled, 6th gear all the way.

Bock

We average about 25 mpg out of both of ours in daily driving. Our daily drives are usually 70% highway, 30% city by time. By miles it's more like 85%-15%. I've never seen more than 29 mpg even on a long road trip in either of them.

You should get out there and enjoy it the way they want you to enjoy it..... WALK to work! Just don't poot along the way, or you'll have to buy some carbon credits.

I've seen about 28 mpg on highway in my 2001 WS6 (m6) with only an airlid and SLP y-pipe + loudmouth. Normal average is right around 20mpg. I got about 9mpg at Summit Point's main circuit yesterday.
But my 91 Honda Civic (no a/c, no power anything, 5speed) gets a low of 36mpg in winter and a high of 42mpg in the summer. :-)
But then again it won't do 115mpg at Summit Point.

I have managed 32 on the interstate in my 2001 M6 when it was stock. It's not much worse now.

I average around 20 in my daily driving on a mix of mostly roller coaster country highway and city bypass/expressway.

I get between 5-7mpg in my 2001 at the track!

I'm always amazed by how much gas I can burn in 5 autocross runs.

21 mpg most tanks (about 75% freeway), low 16, high 25. Driving with the T-tops off does not seem to hurt the gas mileage.

~7 mpg on the track.

~3 mpg for autocross (around 80 runs at an EVO AX school, had a codriver).

1994 LT1 Camaro, M6, with a K&N filter and filter housing, and flowmaster catback.

sounds about right Chuck- i averaged between 21 and 22 mpg over the 30k miles that i had my 2000 Z28... that was a lot of receipts

I seem to be getting about 25 hwy and 16-18 city. It has an SLP cold air intake and SLP exhaust. 6-speed manual trans.

I don't feel that bad, lately(with gas prices like they are), ive been monitoring my MPG. I usually get about 26mpg on a tank with mixed 50/50 hwy/street driving, thats with no burnouts/spirited driving. getting stupid with the throttle takes that down to around 20-22mpg on a tank of gas, still 50/50 hwy/street. I usually let it get down to nearly empty before i refill to try and get as accurate as possible. my daily routes lets me use my cruise down the blvds and coast hills both ways.