2013 Chevy Suburban lt getting bad gas mileage

[chevyguysuburban]

I have a 2013 Chevy Suburban LT with the 5.3 I have a 2 inch front leveling kit on with some 275/60/r20 tires on i have been getting less than 8 mpg on the highway and am filling up 2 time a week only driving 30 miles a day I do fill up when it hits a half tank but is this normal for being leveled?

 

[Doubeleive]

I have a 2013 Chevy Suburban LT with the 5.3 I have a 2 inch front leveling kit on with some 275/60/r20 tires on i have been getting less than 8 mpg on the highway and am filling up 2 time a week only driving 30 miles a day I do fill up when it hits a half tank but is this normal for being leveled?

you are not providing the relevant information needed
how many miles?
when were the spark plugs last changed?
02 sensors? original?
cat's original?
if there is a rat's nest in the air filter and the intake has never been cleaned and your on 180k on the originals plugs, wires and 02 sensors
then yep crap gas mileage.....

 

[kbuskill]

Is this a recent development or did you just get the truck?

The leveling kit shouldn't affect the mileage that much. You didn't really give us much to go off of, like gear ratio, 2wd or 4wd, maintenance history, whether or not you drive it like you stole it?

My '08 with the 5.3l and 4 speed with 3:73 gears averages 18-19 mpg on the interstate running 75-80 mph and around 13.5-14 mpg around town.

 

[mikez71]

e85 or gas?
I'm at 8.7mpg city driving with e85.
(5.3 tahoe 4wd, mostly empty, original 237k mile O2 sensors)

 

[Doubeleive]

a leveling kit should not have that much detrimental effect, I suspect it is something else
the wifes suburban is leveled with 33" off road tires and she still gets 14 easy
the silverado has a 4.5" lift with 33" off road tires and if she drives it it still gets 14, if I drive it 9/10

 

[Joseph Garcia]

Something else is definitely going on with your truck that is impacting the gas mileage. Heck, with my 2007 supercharged 6.2, with 4.10 gears and 305/50x20 tires, I still get 10 mpg in the city and 17+ mpg on the highway cruising at 75 mph.

You did not mention any performance issues with your truck, like feeling 'sluggish' or misfiring, or hard starts, or anything else that may be considered abnormal. Do you have any of this going on?

The folks above have alluded to other possible sources of your low mpg, and I suggest that you start checking them out.

 

[Fless]

Along with providing more info about the mileage, condition, driving habits, and maintenance, put a scanner on it and post up the short- and long-term fuel trims, both at hot idle and at 2,000 rpm.