4.8L v8 Gas Mileage?

[07SilveradoClassic]

I have just passed 10K on mine (07 classic crew cab) and with 50 mile urban commute and several cross state trips, the worst tank was 16.9 MPG the best has been 19.8 (today mostly highway @ 75mph) . most have been around 17.8-18.2

 

 

UPDATE, 12K miles now on the truck, hit 20.9 MPG on last tank, what shocked me was I was hammer down on the highway (80MPH) and had some city stop and go traffic on the tank as well.

[Jagster]

Today I got 21.4 MPG on Highway, But on reg city driving it is about 11.6 MPG... But that's what I get for livin in LA.

[matt04]

My friend gets around 16-17 on his 4.8 driving a little city and highway. I bought a 5.3 and get 19-20 highway stock but hopefully will get a little better with new exhaust and k&N filter

[ropie]

I'm getting about 18 in city driving and when I actually need to get on the freewat, about 21. And I have a Air Raid intake, Power Aid Throttle Body Spacer, Hyper Tech Tunner and Magnaflow Exhaust.

[forgottenmemory]

the mileage is pretty close to what I am getting with the 4.8 in a 2003 ext cab gmc. It is a V8, it has plenty of power to get the job done.

[giant96]

15.5mpg here on a 4.8 500 miles so far..moslty city driving

[ManLuvChevy]

I'm averaging 12 or 13 overall. I drive 40%highway and 60%city.

I have 45k miles on my 2007 4x4 Z71 Crew Cab. I have a 3" Lift and 295/70-17 Nitto Terra Grapplers. I've been driving like an old man too. I go 60mph interstate and 35-40 in city. I start off very slow , very tender on the gas. Don't understand why im gettin such terrible mileage. Anyone else have lifted 4x4 with 4.8L and getting bad gas mileage?