saleenpride1986

the best thing to estimate the mpg is to: fill up to full, write down the mileage on the odometer, then when you fill up again, see what the new mileage is on the odometer and see how many gallons you had to put in to get to full. now divide the mileage driven by gallons filled up.

your car is pretty much stock you shouldn't be getting 10 mpg, i get 11 mpg on average in my car and mines not stock by any means. MJR46 pointed out some great tips to figure out what to do and see if those are the factors. Quite frankly, many things can add or reduce fuel economy.

Projectquick

I put 7 gallons in my car and made a 175 mile round trip. This was all done cruising close to triple digits the whole way. I'd say give your car a major tune up, make sure the gas gauge is working correctly, and if that stuff doesn't help light that bitch on fire because that is terrible.

83glx5.0

so you were getting 25mpg doing 90 somthing? I find that hard to believe....

Projectquick

Close to it. I was cruising at 75-80 most of the time with about 1/4 of the trip in the 90+ area. I have stock 3.27s and all that emissions and A/C BS off. I didn't believe it but I barely made it to the gas station so I know that tank was damn near empty and I think it was like 7.2 gallons for 25 bucks a few months ago.

bigjbuff28

prove it

Projectquick

Prove what? I don't care if you beleive me or not really. You know what, you pay for my gas for me to drive where you are and I'll put in 7 gallons of gas and cruise at 85 mph until I run out of gas, I bet i'll get about 17-175 miles.

Portmaster

So what kind of mileage do you get going back up the mountain? lol

nseoi

the BEST i ever got was a trip from disney back home in miami, i got 24mpg doing 80mph (just under 2k rpm) in the middle of the night on cruise control with light rain. i have a mildly modified 5.0. On the street i usually got between 9 and 12 mpg cause of the heavy traffic. i have not had a speedometer cable for most of the year so i could not calculate my mpg after my full exhaust and EGR delete. i figure it would have gone up a tad bit but who knows, i just got the speedo working again not too long ago

Projectquick

Again, not like I gain anything from lying. I'm telling you I put just over 7 gallons in and made a 175 mile round trip not driving like a grandma, either you believe or not, I'm not losing any sleep over it.

67mustang302

I think mine has a fuel leak at the accelerator pedal. Haha.

Seriously though, I don't know what some of you are doing to get such crappy mileage. I have a carb'd 302 and get about 20mpg combined city/highway, putting my foot to the wood a lot, driving up and down a mountain across a 4,000+ft elevation change at speeds anywhere from idle-80mph. And this engine sees over 6,000rpm several times a day.