Anybody have a tow vehicle using the 6.0 smallblock? Mostly used in 3/4 trucks or suburbans. If so, how many miles and how's it doing as far as reliability? Any piston slap issues? Thanks!

I have the 325 horse 6 liter in my 2002 Sierra Denali. It tows great and the engine has performed flawlessly. No noise of any type.

I've got an 02' K1500HD. Plenty of power to pull the trailer & 67'. Yes, It does have piston slap noise on start up. Previous to this truck I had an 00' C1500 with 5.3L WITH piston slap and before that one I had a 97' K1500 with a 5.7 vortec which also had piston slap on start up. I put 89,000 miles on the 97' and the 00' had 92,000. All of these trucks ran well and never had to be warranteed for any repairs. The piston slap issue evidently is more of a PITA. While all of these trucks have given me good service I still can't understand why GM can't put together a motor without piston slap. In my mind, Chevy has always had the best/most powerful gasoline engines and thats why I've stuck with them. Diesel is another story. Dodge now has the hemi which advertises good #'s but I'm hearing of alot of bugs still being worked out.

word round the shops round me is that 6.0 motor is designed poorly and might be prone to leak. i think its because they just started making them not to long ago. they are going in the vettes soon as well as pedal shifters on em, and the next camaro is going to have the 6.0 in it as the top of the line one, the middle of the road will have 5.3L and the bottom end camaros will have a 3.5 L or a 3.9L v6.

I have used many 6.0s over the years. the crew cab I had at CB03 had one and I got 11.7 mpg towing my 68 on a steel floored trailer for the 700 mile round trip. power is way more than enough for this kind of application.

the piston slap in 6.0 engines was supposedly caused by the assembly proceedure for attatching the rod to the piston at the factory. GM says the noise has no affect on durablility and will stand behind the engine even after warranty has expired. the '03 and later 6.0 engines are supposed to have corrected this noise issue. my '03 crew cab has not made a sound yet.

these engines leave the Ford 5.4 and Dodge 5.9 in the history books. ancient history!!!!

What MPG do they get in normal city/highway driving?

my experience with the HD 1500 with 3.73 axle is approx 15mpg for combination driving. I like this combo better than the HD 2500 because that combo requires 4.10 axle. less mpg for sure. I have not needed the additional power of the 4.10 for towing a car trailer. livestock trailers or heavy RV trailers might require it.

hope this helps.

I typically average 14.9 mpg. My truck has the 4:10 gears.

I also have a 2003 GMC Serria 1500hd,3:73 rear with 20000 miles on it gets 14mpg combined driving no piston noise in the morning and plenty of power for towing my enclosed 24' trailer.

I have a 2003 GMC Sierra Denali with the 6.0 in it. Only 1400 miles on it but no problems. I installed a Westers custom PCM today and dramatically improved drivability and performance. I highly recommend this upgrade, as do many members of the Sierra Denali/C3 newsgroup I am a member of. Free upgrades for life and he can do most anything you request. Even adjusting programming for supercharging.