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getting an 8.1 to get high teens mpg

buffblazer

1/2 ton status
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Jan 5, 2005
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Fort Collins Colorado
is it possible? this goes back to the thread i started about the 8.1 well the truck is still for sale and i was gonna go look at it, i need this as a DD though, about 40 miles round trip a day when im in town and i want it to last a long time.

i have the money now to put goodies in it and was hoping to get the milege up in the high teens that way if gas prices sky rocket or if times get tough im not being killed by the fuel.


chip it, exhaust and cold air intake are gonna be the first things but what else can i do? supercharge it?

looking for realistic suggestions

this is the truck im looking at

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15478360287_277292167_IM1_02_565x421_A_562x421.jpg

15478360291_277292167_IM1_05_565x421_A_562x421.jpg
 
Its drive by wire so how about you cap the throttle at 25% lol.

Really though i dont think its gonna happen without regearing to like 308s.
 
No way.

All the bolt ons in the world won't raise the mpg another 2-3 mpg at best even if you keep your foot out of it.

A big block in a fullsize 4x4 crewcab pickup that weighs 6000lbs or more empty with the towing gears that thing is bound to have WILL NOT get good gas mileage. You'd be lucky to see 13mpg with that thing.

Sorry man, not trying to be rude but pipe dream.
 
If your weight was around 3k, maybe
 
I had an identical truck and was lucky to see 9 empty. I traded it for a D-max, that got the mileage up..lol. When I wanted out of it no body would give $hit on trade cause of the 8.1. I ended up trading it in WI, driving out and driving new rig home. That truck seems pretty pricey to me, granted mine had cloth buckets, and no roof. I think i payed like $14K for mine, with 1/2 the miles.
 
Its like 500 ci, just take fuel to run something that big. I don't think it will ever happen. Mine that I had in 2000 just got 10 no mater what. You my be able to spend some money to help it, but I think you would better off to spend the more money an find a duramax if that is your worry. Mine will get 15 to 16 in town and 18 to 20 on the highway.
 
The 8.1 is a pig. It makes good power but will never get good gas milage. I almost bought one before gas went nuts and was around $1.20 a gall.
 
Like I said. Regear to 3.08s and drive it easy I bet you'll get in the 20s. All the old BOPs were 4500lbs boats with 500ftlb 455s in them and got ridiculous MPGs because of the gears. And thats no fuel injection and no overdrive.
 
Don't think there's anything lower than 3.42's for that front axle...I think...
 
Is 5mpg worth the extra cost of a DMAX that uses more expensive fuel? I've looked around a little bit here, and the Dmax trucks are A LOT more expensive.
 
is it possible?

I can get 14+ MPG on the highway with mine (i have a K&N CAI and a Diablosport Predator. I only get about 10 MPG in town though.

That is a sweet truck, but for that price you could get a dmax with more miles.
Spending that much on an 8.1L and then having to dump another $700+ to get it max efficiency might not be the best route to go.
It does have the 6 speed Allison though, so the double OD might help a bit w/ the mileage.

If you are set on a 496, I don't think you are going to find a nicer truck than that, so might as well go for it.
 
I can get 14+ MPG on the highway with mine (i have a K&N CAI and a Diablosport Predator. I only get about 10 MPG in town though.

That is a sweet truck, but for that price you could get a dmax with more miles.
Spending that much on an 8.1L and then having to dump another $700+ to get it max efficiency might not be the best route to go.
It does have the 6 speed Allison though, so the double OD might help a bit w/ the mileage.

If you are set on a 496, I don't think you are going to find a nicer truck than that, so might as well go for it.


i was gonna try and talk them down on it, and im not really set on the 496 i just fell in love with this truck. i wanted the 6.0
 
My 8.1 doesn't use a whole lot of gas...






































cause it sits in the driveway while I drive the K5!:haha:
 
My 6.0 wasn`t a pig, my Yukon XL w/6.0 is though. I think EFI live or someone can tune it for mileage.
 
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