I've had our 2006 Suburban for a couple of months now. Right now I seem to be averaging 11.8 mpg.
Mostly in town city driving 35-50 mph with some freeway driving hops 65-75 mph speeds. Average ambient temps hover at 100* +.
I don't think that's too terrible for the size of the vehicle.

2006 Suburban LS,149K miles, 5.3, 2 Whl. Drive. Using 87 Octane Unleaded. Goodyear Assurance P265/70R16 A/S tires 35 psi. 100% Stock.

I am going to be installing a cold air induction soon. We'll see if it does anything to increase MPG.

What are you guys getting for MPG?

 

Here in cooler W WA our 05 (no longer own) averages about 15mpg every day driving, 18 road trips freeway. My wife says our new Tahoe is 18-20. Our 93 Sub was also in the 15-18 range

 

Ordered a CAI for my 06 5.3 Burb.

Don't know if it will make much of a power difference but I am hoping to bump up the mpg 1 or 2

 

2001 K2500, 6.0L with 4.10 gears, 95% driving highway 70-80mph, 11.5 mpg, towing 10 mpg.

 

Make sure the CAI get along with each other, BTW I saw a 67 Camero on the side of I-44 in Tulsa today

 

Make sure the CAI and MAF get along with each other