8.1L gas mileage

Anybody done any mods to their 8.1L HD that gained any gas mileage?

FYI- A supercharger does not help, nor does a lift, big tires, cold air intake system or any other add on to give you more horsepower. But, you probably knew that. :)

8.1 and fuel mileage...isn't that a contradiction of terms?

My 8.1L gets 4 miles to the gallon in town and 10-12 miles to the gallon on the freeway, and thats only if some lowly ford owner doesn't try to run with me, which ends up costing me about half a tank of gas after I put 5 or 6 car lengths on em......

stick to the highway and tuck in behind those semi's

You can't tell me that by opening up the intake and exhaust that I couldn't gain something?

Your on the right track, a dual flowmaster or magnaflow on the back end and a high flow air filter or cold air intake will give you more horsepower. The computer will adjust the fuel mixture based on the increased air intake, therefore it would allow more fuel thru. You might actually get more power per the drop of gas with the better air flow, but you will still use just as much fuel. Did that make sense?

Yes, it makes sense. I guess filling 496 c.i. with gas takes it toll. Don't get me wrong, I'm very happy with the truck...just want the best of both worlds (power & mileage). What kind of HP would I see with a Borla exhaust and different air intake? What about a throttle body riser?

try irdium spark plugs

I have done intake, 4" magnaflow exhaust, Hypertech, new plugs... all that... I have had H.P. gains for sure, but the gas milage has NEVER changed.... 9 in town... 11 Highway...

Well I'd assume that TB Spacer would help, or as you said more air flowing but maybe not. but when it is 496 cid in a truck you shouldn't be expecting mileage. Maybe one of those hypertech programmers would help but I wouldnt expect much.

y would chevy do this in the first place? they claimed that it was gunna be good on milage but geez lol