dusfermc

Just to clarify, I did follow the breakin guides for the first 800 miles. It wasn't til like 810mi that I got it up too 4500rpm.

rutbuster1

Ha. If what you did hurts it then mine is ruined! lol I purchased mine this past Saturday and it had right at 100 miles on it. Before I knew it, I was running 75 on the interstate. Not meaning to. The book says not to pull a trailer or drive over 55mph for the first (I think), 500 miles during break in. I've talked to other people and they said that as long as you don't really stomp it, it'll be fine. Just don't abuse it.

dusfermc

What do you think about the AFM?

JeffG

Your fine. I have a 2006 Tahoe and a 2011 Traverse I have let the RPMS get high on both during break in. I have 130k on my Tahoe and no engine problems or oil consumption. The 5.3 engine is a strong engine enjoy your new truck.

dusfermc

That's the type of answer I was looking for thanks!

rutbuster1

Excuse my ignorance, but what is AFM?

dusfermc

Active Fuel Management (v4 and v8 might ring a bell in your DIC)

rutbuster1

Oh, I looked it up in my book and found it. I like it. It mainly works on the interstate though. In town, it stays mainly on V8 mode because of all the stop and go movement. I've had no problems with it, but of course I only have 450 miles on it.