97camaross

iTrader: (6)

My father has been looking at this truck that is for sale it is a 2004 GMC 2500hd 4 door 4WD with a 6.0L and 4L80E... The truck is in perfect condition inside and out the only down sides are it has a 6.0L and it has 198000 miles...well is it possible to get good gas millage out of this truck? he is willing to do any thing from long tube headers, no cats,tune,different gears,CAI... You get the picture...Is there any proven methods of getting better gas millage out of this truck?

ls6firebird

i got about 16 on the highway in mine with a diablosport predator. it town about 12 or 13. wish i still had the truck

ZONES89RS

iTrader: (25)

Good for a truck? Yes, good in general, no. A few bolt ons and a tune will help allot(cat back, cold air).

flatblackz

iTrader: (2)

headers, catback, cold air intake (KNN intake setup), royal purple oil, weight reduction if possible, no mudder tires (use regular street tires), no fat chiks.

GreatWhiteZ28

iTrader: (15)

I would put that one under the weight reduction/weight maintainability section of the "Gas millage for dummies" book....

jrm1493

Even in my weak V6 truck I struggle to get about 17 city / 19 highway. I would think you'd do a bit worse that that best case, but not that much worse. In my experience most trucks do about the same regardless of engine/transmission combo. Big tires will drop your mileage a lot, but driving style is the most important factor (stay out of power enrich).

The thing that made the most difference for me was getting some little skinny SUV (road) tires (235/70/16 or something). And try not to use the brakes - if you drive so that you don't have to hit the brakes very much you're not wasting much energy as heat so you're converting most of the energy to forward motion not brake dust. And by not using the brakes I don't mean hit stuff, I mean accelerate slowly and leave a lot of room between you and the car in front, so that when they slow down or there is a red light you just come off the gas and coast until you need to hit the brakes. Modern engines have a mode called DFCO (deceleration fuel cut off) so that if you are above a certain RPM and come off the throttle you will use zero fuel (engine will be driven by the wheels). Use it, it works pretty well.

I don't think there's much you can do engine-wise to improve the mileage in a significant way. The OEMs pretty much set their vehicles up for pretty close to maximum mileage since they have to pay penalties on fleetwide mileage numbers.

ls6firebird

id say one of the biggest factors in a truck like that is gonna be the gears. i had the same truck on 32 inch mud tires and 4.10 gears. i dont know what gas mileage it woulda got without the predator, i never ran the truck without it. but with it, it got good gas mileage, was a very comfortable truck to drive, and pulled great. best all around truck ive had

97camaross

iTrader: (6)

see he wants a truck that gets around 15-16mpg but this truck may be too good to pass up he may just take a hit on the gas millage....

ls6firebird

they really are great trucks. i cant wait to get another one. i pushed mine to the limits and never had an issue