GM 8.1 liter V8

BLACKTJ97 · Feb 26, 2007

Has anyone had any experience with this engine good or bad.

crash2 · Feb 26, 2007

How much you wanna know

TreeClimber · Feb 26, 2007

crash said:
How much you wanna know

How many gallons to the mile does it get?

Lucky Jeff · Feb 26, 2007

I'm kinda curious how many problems it's had..... And if it's with the motor or the crap stacked on top of it.

BLACKTJ97 · Feb 26, 2007

I know the mileage isn't great. I'm assuming 10 to 12 if you drive nice. Does the engine have any problems. I've heard the 5.3s have head issues, but haven't heard anything about the 8.1. I'm looking at a 2001 GMC 2500 4x4 with an 8.1 for a tow rig and want to know a little about the engine.

Thank you,

TreeClimber · Feb 26, 2007

BLACKTJ97 said:
I know the mileage isn't great. I'm assuming 10 to 12 if you drive nice. Does the engine have any problems. I've heard the 5.3s have head issues, but haven't heard anything about the 8.1. I'm looking at a 2001 GMC 2500 4x4 with an 8.1 for a tow rig and want to know a little about the engine.

Thank you,

The 8.1 derived from the venerable 454 big block. It's well designed from what I've heard. But don't EVER expect 12 mpg. EVER. Like in NEVER. Especially if you're towing. You want economy and power, it's diesel time.

79chevy39.5's · Feb 27, 2007

lets see 8.1 is a powerful gas motor.........so bad gas milage good hp and not as much torque as a desiel good tow rig for lighter rigs and people who dont care to spend the extra money on the d-max also if only used to tow

Lucky Jeff · Feb 27, 2007

I can understand why people don't want to stray from Gassers. They definitely drive different. But the benefits easily outweigh the negatives on the diesels nowadays.

Halfrack · Feb 27, 2007

i have see 13 unloaded on the freeway doing 60 65 mph and 7 fully loaded. but its mainly the tranny because it doesn't free spin when you let off. but has lots of power

Jaydog · Feb 27, 2007

TreeClimber said:
The 8.1 derived from the venerable 454 big block. It's well designed from what I've heard. But don't EVER expect 12 mpg. EVER. Like in NEVER. Especially if you're towing. You want economy and power, it's diesel time.

Diesel time? My neighbor gets 9 mpg with his '06 Cummins, I'm scared to see what I get with the 6.7.

TreeClimber · Feb 27, 2007

Jaydog said:
Diesel time? My neighbor gets 9 mpg with his '06 Cummins, I'm scared to see what I get with the 6.7.

Somethin' wrong.

Cummins get better than PowerStrokes. And my PS gets 12 loaded / 15 empty. I even get 10+ doin' 85 mph with camper, trailer, jeep and in the Rocky Mtns.

Either he's broke. OR has a chip turned way the fawk up. OR somethin.

crash2 · Feb 27, 2007

10-13 seems to be the norm unloaded. As for any major issues---I have only seen one broken enough to replace(chewed up #1 pistion). The only issues we had were oil consumption and it had to do with the intake bolts causing oil seapage into the motor internally being burned. But overall we have good luck with the motor.

As for the 5.3's having head issues---never heard of that...

Jaydog · Feb 27, 2007

TreeClimber said:
Somethin' wrong.

Cummins get better than PowerStrokes. And my PS gets 12 loaded / 15 empty. I even get 10+ doin' 85 mph with camper, trailer, jeep and in the Rocky Mtns.

Either he's broke. OR has a chip turned way the fawk up. OR somethin.

That's what I thought, He is taking it into the shop to try and figure out why it is so bad, it is bone stock with 25K miles on it.

motoman432 · Mar 1, 2007

the 8.1 is a good motor i know guys that pull 28' car trailers and camper trailers and get 10 mpg all day and with no load still get 10 mpg. there are always ways to improve gas mileage to with letting it breath better. but depending on what you are towing and as for a gas motor why wouldn't you get a 6 liter??

BLACKTJ97 · Mar 1, 2007

A 6.0 is what I was looking for. But I had found a good deal on a 8.1. Last night I bought my truck though. The wife talked me into a 6.6 dsl. It drove nice in the snow last night. Kind of odd just pushing a button for fwd. Thanks for all the comments. Crash I have a freind at a dealer that said they had two trucks with 5.3s that had head problems. But thats not very many compared to all the trucks out there I suppose. Thanks again for all the imput.

Lucky Jeff · Mar 1, 2007

Props to the wife :clappy:

I've towed with the 5.3 and the 6.0... it's Amazing how big of a difference there is between the two.. 5.3 is a pile.

motoman432 · Mar 1, 2007

sweet you got a great tow rig on your hands now. always a plus that the wife was the one who wanted it too. now its time to get some more power out of that d-max

skweeks · Mar 8, 2007

A friend of mine had a chev w/the 8.1 and it almost had to much power. It would out pull anything (stock vs stock) but yeah gas mileage sucked really bad. If i was you I'd buy a CUMMINS you cant go wrong there. It seems everyone wants the 12v and not the 24v. I guess it's cheeper to pump up. My cousin has an '02 with 750 hp, little over 1500 lb-ft and huns low 12's in a quarter mile. I've got a '97 12v and get about 18 mpg in town, over 20 on the freeway, about 14 mpg towing and never been happier. BUY A DODGE!

Lucky Jeff · Mar 8, 2007

skweeks said:
A friend of mine had a chev w/the 8.1 and it almost had to much power. It would out pull anything (stock vs stock) but yeah gas mileage sucked really bad. If i was you I'd buy a CUMMINS you cant go wrong there. It seems everyone wants the 12v and not the 24v. I guess it's cheeper to pump up. My cousin has an '02 with 750 hp, little over 1500 lb-ft and huns low 12's in a quarter mile. I've got a '97 12v and get about 18 mpg in town, over 20 on the freeway, about 14 mpg towing and never been happier. BUY A DODGE!

you're too late... he already got a truck :flipoff:

BTW... who's your cousin?