Long term reliability of GM 8.1 Liter

To the OP:

You might want to check out the class "A" motorhome forum. There were a few of them that used the Workhorse chassis that had the 8.1L.

I have read on the workhorse website that the 8.1L is designed for a 250,000 mile service life, same as the Duramax.

My 2003 with 120k miles uses some oil(I think all the 8.1's do) and averages a decent 9.5mpg towing my 34ft TT. I feed it Mobile 1 synthetic and top tier premium fuel. I haven't noticed piston slap, at least not any more knocking at startup than any other vehicle I've owned. I wouldn't trade this gas towing beast for anything. Well, maybe for a brand new loaded up one with a 6.2L with an 8 speed. Actually, Now that I think about it, I rather like the 4 speed with tons of torq and Hp. It doesn't have to shift much to stay in the power curve.I change my mind. No trade.

Great motor just thirsty. Will pass everything but a gas station.

a friend of mine has one of the ones built in the late nineties and he still drives sit every day. goes to Yuma every year and had only one problem and that was with the air conditioner pump.

About as reliable as an anvil. Yes, they are that good. :)

I have the 8.1L in my 2001 Chevy 2500 Suburban but only have 50K mileage on it and have had great reliability with no problems. I bought it from the original owner that had it for 1 year and used it to tow a horse trailer putting 25K in one year. I used it primarily to tow my 32' Avion and my 20' enclosed car trailer with my 63 Grand Prix and no problems to date with the engine. It is much better than the 7.4L I had before.