Long term reliability of GM 8.1 Liter

We bought our 3500 2wd chev dually with the 4:10 diff. Traded it in Dec of 04 for the same truck but a duramax. 8.1 and total truck at 58K miles was still a new truck to us. 05 duramax is a better towing truck but I would be happy if we still had the 2001. Gas engines are nicer for town driving I think. Not true maybe for the newer truck as they are awesome.

chevman

I've owned it less than 2 years, but mine currently has 140,000 miles on it and runs great. It does burn a quart of oil every 2-3000 miles. We got 7.5mpg towing last year, 10 around town, 12.5-13 on the highway. You can get 13-14 if you drive 65 max. We are loving it so far and plan to tow several thousand miles with it this year.

130 miles, 2001 Silverado only work done is 2 crankshaft position sensors. The Allison, oil pump, warranty and shift control module. Pull 26 foot travel trailer, snow mobiles, atvs. Rides like a caddy. Plan to be buried in it, foot on the accelerator, blowing through the pearly gates.

For those that asked about the 6.0L w3/73 RE-- a real workhorse too. I traded my 6.0L 4x4 SB in last year, and not due to the engine -- but the rest needed more work than I was willing to do ...

I bought another one (2015) 6.0L and love it too. A great engine. Got the 4:10 in this one - but would take the 3/73 again over 4:10 if it was offered. It's not... Best mpg ever on this one 18mpg on highway empty, but more often 16-17

When hauling, about 12 mpg, but it pulls all day long...

I don't know what was wrong with those pigs. 2500s with 8' service beds on a campus that was mostly 15mph limit. Craig

About 3 years ago while pumping gas I was next to a guy filling up an 8.1L/Allison tow truck.

I was truck shopping at the time & I asked about reliability; he said he had either 300k or 400k (it was 3 years ago, don't remember the specifics) and it had been prefectly reliable. And that's in a tow truck (lots of idling, stop & go, etc).

Turtle n Peeps wrote:
About as reliable as an anvil. Yes, they are that good. :)

Or perhaps "Like a Rock" :B... Big block Chevy's is about as good as it gets for durability.

Bought a 2001 Suburban with the 8.1 & 4.10 at 50k and sold it at 135k. Used it to tow 8k and run around town. Was a strong rig. Only thing I ever needed to do with the engine was put in a new set of spark plugs at about 100k. Sure, they use oil (mine was about 1 qt per 3k) but it was a very reliable engine. The fuel pump went out (nothing to do with the engine) at 120k but who can blame it after pumping more than ten thousand gallons. ; )

I got about 10 mpg in town, 13 or so on the freeway.

2002 2500HD Crew Cab Long Bed 4X4 8.1 Allison 230,000 Whipple Supercharged trouble free miles. My brother bought it from me and is driving it today. Best truck I've ever owned. Only draw back is, it's a thirsty beast. :)

Wow, 5.0 mpg? I have a 2002 2500 HD long bed extended cab and I get 14 mpg solo and 8.5 - 9.5 towing a 40' fifth wheel. I have 100,000 trouble free miles on it. And, I think I have jUst experienced my first issue, which according to the folks on the GMC Truck Forum, sounds like an exhaust manifold leak. Did I mention. I LOVE MY TRUCK?