2008 GM 6liter.

I presently own and tow with a 2008 GMC 2500HD Ext Cab 6.0 with 3.73. Very happy with the truck hauling Cruiser CF29BT (9500-9800 lbs loaded with 1600-1650 pin weight). Sure love it gas but oil consumption is OK. Just over 70000 miles.

Great motor ,I put mine through masonry contractor abuse every day ,its allways loaded up and it comes back for more, very low maintenance, couldnt want more from it.

I have had two 6.0's. a 2003 1500HD and my current 2010 2500HD. I tow an approximate 9,000LB (when its loaded) 36 foot trailer. I change my oil by the computer. Probably get approximately 5-6000 miles between changes depending on towing I change my own oil and have always used Mobil 1 10w30. The truck has 75,000 miles on it and I bought it new. The 6.0 holds 6 qts. of oil and at each oil change I have always gotten about 5 out of it. I really like this truck and engine, but it is very thirsty.

I can't speak for the new ones, but I have an 03 6.0 with 145,000 on it and uses no oil towing or not.
i run Mobil One 5w-30 and change it at 6,000 miles.

Presently have a 08 2500 Burb with a 6.0. It works great towing a 28' Alpenlite.

had a 07 2500 HD new body style with 6.0, no issues with using oil, good solid truck.

I'm at 140k on my 09 6.0. No oil usage whatsoever and I tow either a camper or cargo trailer with it, so I'd guess 50% of the time I pull out of the driveway it has something hitched to it. Great truck.

Have owned two 6.0 suburbans and I will add to the fact that these engines are quite bombproof . They do take down a little oil with miles , but on my 2000 sierra with 300,000 miles and my 2000 suburban with 200,000 miles I switched to 10w30 and they hardly use any oil.

We have three 2500 6.0l trucks at work, two are 2002 and the third is an 05. These trucks pull trailers that weigh around 6000 lbs every day locally and have been rode hard and put up wet. One of the 02's has around 140k the other 130k, the 05 has 95k. Both of the 02's have been problem free except for a bad trailer hitch on one. The 05s drivetrain has been solid but little things have been giving us issues, the blower motor for example. The 05 is usually down a quart by the time it is due for an oil change, the 02s not so much.

OP I have a 6.0 and very pleased with it. I have owned 2 thus far and have no issues. GM did a great build on this engine, very reliable and pulls without and complaints. I sold my last one with high miles and it had been worked its entire life. Only issue was CPK sensor, fuel pump, and exhaust Manifold studs other then that I changed the oil, coolant, spark plugs and filters. Replaced the water pump and CPK sensor as well. On the newer generation one that I have, I have not done a thing. Only maintenance items only, filters and oil change. I really like the newer one with the 6 speed auto. Yes you will find several older 6.0 engines with well over 200k with a lot of worked miles. So my personal experience has been great with these engines.