Just a question to ask everyone. I'm curious to see what everyone is getting either stock or with mods.

I've heard a couple people say they average around 23 or 24 on the highway with their L98, and i get around 15.. kinda bothers me

all i have is cold air intake, edlebrock headers, 3in exhaust, no cat, 180* tstat. and i get between 12 and 15 in town or highway..

so what do you guys get?

 

We've done plenty of these threads. Do MORE searching. You didn't specify your MPH, nor your axle ratio, nor your elevation.

 

i get around 12 in town/20-22 hwy from my mild-mods 350 crossfire/700r4/3.42 rear

 

Well w/ a cold air intake, full 3'' exhaust, headers, & a 180* stat, its no wonder the mileage is low. Try a 195* stat & see if your mileage improves.

 

i did a search with gas mileage in the search box, looked through 2 pages worth and didn't find what i was looking for.

also my axle ratio is located in my sig AND on the side under my profile pic

 

thing is that my mileage was about the same with a 195* installed. only reason i did a colder one is that i needed to replace it and had this one on hand already

 

I get 16-18 in city, with a mostly stock 5.7 (no smog pump, headers, and spectre cold air intake) but I like to get on it a lot. Could see getting around 20 if I really babied her. Haven't checked it on the highway. I was getting 10-12 before I replaced o2 sensor though, I would check that first.

 

My CEL would be on though wouldn't it?

 

I get around 22-27 mpg on the highway and around 15-17 in town.

 

Not neccessarily, no. If its failing, but hasn't given out yet, there wouldn't be a code. These sensors weren't designed to last all that long, and its a fairly cheap one (around $20) so id just replace it and see what happens. Other then that, a basic tuneup can work wonders too.

 

I did a fairly basic tune up this year when i had the engine out and replaced seals and gaskets. Replaced plugs and wires and timed it. I should probably do a fuel filter at some point.

It does seem like the car runs fairly rich though most of the time.. and even before i removed the engine it seemed to run a little rich.

 

Running rich is leading me to think possibly o2 even more.

 

If your fuel filter has never been replaced, DO IT NOW! So many times I've seen a new fuel filter really, really helping out a car over a clogged one.

 

Haven't replaced the fuel filter in my '92 Z28 in about 5 years, car is currently Sitting in my garage in Retirement, till I can afford the gas & expenses to fix a few minor things, some tlc, but last I drove it was getting 16/18 city & 24/26 hwy when I really drove it as if it were a Minivan, absolutely NO hard takeoffs no sudden braking or hot rodding off the green lights or Blowing by everybody else on the Freeway, it got what I consider good mpgs and I didn't have to abuse it. But when I first got it that I spent a weekend just Roaring thru the Streets and Freeways of L.A. I got maybe about 8 mpg in the city and 12 on the Hwy

 

I've only owned it 2 years. I haven't changed it. Not sure when it last was