DeucesALLin

I am looking to get a suburban for long highway trips.

Have decided on the GMT900 models... and will plan on AFM delete from the gate.

What are your experiences with the 6.0L burb, and would you pick that over a highway cammed 5.3 burb for extended cruises under low load?

Jonblarc7

My brother in-law has one it's an 09 2500 loaded Suburban un-tuned with CAI. It is a dog but a comfy ride. It gets around 12 to 13 mpg no matter how he drives it. Now this is un-tuned and I imagine a tune and headers really would wake it up.

I also have another friend that has one completely stock. He uses it to pull his Nautique G23 wakeboat and kids from TX to NC every summer and back at the end of the summer. It does fine and the boats weighs about 8,500 pounds. I don't even ask him what kind of gas mileage he gets.

FFDP

iTrader: (2)

There are two versions of the 6.0, one for the 1500 and one for the 2500.

The 1500 from 2007-2009 has AFM/DoD. From driving lots of different versions through previous jobs, the 6.0 did have more grunt but suffers form mpg loss. So if all freeway miles are what you are after, I'd go with a 5.3 and do the camshaft swap in that.

Also consider going newer than 2009 because the 4L60e is not a transmission I want. 2010+ is a standard 6L80e for all 5.3 trims.

1994Vmax

iTrader: (4)

You won't find an SUV equipped with an L76 anyway so it's of zero concern. If you want a 6 liter Suburban it's a 3/4 ton with an LY6 or an L96 anyway and none of them have afm. Anything with a 5.3 is a 1500 and has afm. The 5.3 will get better mileage afm deleted or not and 2010 up is a safe bet for the 6L80e.