[Scrapdaddy SR.]

From time to time I keep hearing "rumors" of people getting up to 32 MPG(highway use) out of thier 5.0 with proper tuning and a few mods done to their cars.

Any truth to this? if so what was done to get that much MPG out of their engines?

[dr.gonzo!]

I think thats the other way around. I can see a 5.0 getting 23-28 mpg. I dont belive in the 600hp 35 mpg civic either. More hp means more gas.

[Drick]

I've only seen about 23-26 MPG

I get 21MPG if on A good day if I keep my foot out of the gas but normally 20

[g money]

Well, early EFI stuff was real trash, so if you tune it well, you should be able to extract 10-15% better fuel economy, plus some added power. In this case, you can improve power and economy, because you tune for power at the higher end, and economy lower down.

[nolife]

I made a couple coast to caost trips in my 91 wth 2.73 gears. Going between 75-80 (closer to 80), I had quite a few tanks that I averaged 28MPG. This was with 4 people (two were kids in car seats) and the hatch and various nooks and crannies completely full of stuff. The car was completely stock including air silencer.
I'll take a Mustang packed with stuff over a roomier SUV or minvan for that trip any time.

[Haggis13]

I wish I could get mileage like that. Horsepower is king though!!

[Scrapdaddy SR.]

Thanks, I realize my question was a little short on details. As far as mods go I was thinking of better air flow and possibly a little boost in compression.
Not looking for big power as the 5.0 even in stock trim should be enough power for the "project" car it will be going in. Also the "project" car will weigh in (with the 5.0 motor and transmission installed) at around 2,800 LBS. Correct me if Im wrong but the average V8 mustang weighs in at around 3,200 to 3,300 LBS.
The Advantage of the Mustang body over the "project" car is aerodynamics.
I can get about 22 -25 MPG on average with the stock 120 HP 6 cylinder motor in the car now. So Im thinking and additional 100(+/-) HP and possibly similar MPG is a great Alt. Power plant. Plus the advantages of the 5.0.First my son scored the motor for FREE! IT weighs 48 LBS less than the 6 banger. Add(aftermarket) aluminum heads, possibly take another 80 LBS off the car, Aluminum radiator.... ya get where Im going with this. This car will be my daily driver so thats whay Im looking for the most "bang for the buck".
And probably the best part is having that distinctive 5.0 exhaust tone!!
Id try and post a pic of the"project" car but it gets blocked.

Thanks again for your imputs, Keep em coming.

[TurboLX]

i get about 30+mpg, seriously