I am looking pretty close at a couple of these in a regular cab truck. Is there anything I need to know? I had two 2005 5.3's without trouble. I seem to recall some talk about issues on the newer ones with AFM and oil consumption. Is this something I can tell with a test drive or mechanic inspection? Anything else to look at for the 08-13 Chevy and gmc trucks. Thanks.

I believe the 5.7 was completely redesigned in 2011 ...and now holds 8.5 quarts. There were a lot of issues with the old design but have not heard any with the new design

There hasn't been a 5.7 since ~1998. I do believe that you are right that those years had oil consumption issues due to the AFR, I'm not sure about diagnosing other than long term monitoring of oil-consumption. It's definitely something I would ask the seller, if they acknowledge it's been addressed then you should be good.

I could be wrong about this, but I seem to remember reading that one could buy a tuner that could turn off the AFM.

That's correct. Many have seen better mileage with it off.

Correct I was thinking the engine previous to the redesigned 5.3 was a 5.7 for some reason. A guy at work has a 2011 GMC sierra and the engine self destructed at 75K. GM replaced it gratis

To the OP make sure you use Dexos certified oil , it was developed just for these engines.

I have a 2009 5.3 that was replaced at 50k due to oil consumption. Currently have a little over 90k on truck with no further issues.

How much oil was it burning?

I'm sorry i missed this post. It wouldn't have any oil on the dipstick at 1k after oil change. Close to 2qts in 1k.

That was not good. I don't think I have owned a car or truck that burned more then a quart at 5k intervals

Wow! That's a lot.

On another note, the used truck market is crazy. I am having trouble finding anything that ha less than 100k for less than $18,000. When you can get a new 2500HD reg cab 4x for $30,000, it's hard to drop nearly $20,000 on a 3-8 year old 1500 that may or may not burn a ton of oil.

They replaced the engine at 50k and truck is currently at 92k and has been absolutely perfect since engine swap. Not a leak one and no engine light. Good luck in your search.

Same here , I just looked at a 2011 Silverado extended cab with almost 100 k on it for 27k and he was not budging. I can buy the 2017 version with a double cab for 35k.

Some years ago this forum had discussions about the best axle ratio for the 5.3L. 3.73 was the consensus. Anything lighter would shift out of overdrive at any hill. I've no personal experience, my 2009 is a 1T dually with 4.10 axle ratio.

2012 5.3 with 60K and it doesn't take any oil between oil changes every 5k miles.