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5.3 mpg mileage problems

Olie24

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Olie24 New Member

Olie24

Posted
Posted

Hi, Ive been having a problem with my 2000 Silverado 5.3 vortec, and it has been getting horrible mileage. Right now I have 229 miles on it and the low fuel light is on.
I have a Spectre CAI, I run 285/75/16 cooper stt tires, and i have a leveling kit and 4 inch blocks in the rear, and also have dual straight pipes back to 4" tips. I have been getting around 8-10 MPG and i drive about 45-60 mph average on gravel and highway.
My question is, what is causing this? I know I shouldn't be expecting 18mpg or anything, but to me something isn't right. Ive replaces the fuel filter, cleaned the throttle body, air intake is pretty new, and oil is always changed every 4000-5000 miles. so i don't know what my problem is but any help would be appreciated. Thanks.

kstruckcountry Senior Enthusiast

kstruckcountry

Posted
Posted

Clean MAF, check O2 sensors....

To be honest that sounds normal for that setup, none of the guys on here with 285's brag about their fuel mileage lol

Tucker Enthusiast

Tucker

Posted
Posted

Those tires are a killer on mpg's. And the straight pipes probably don't help either due to the fact that your right foot is harder on the gas pedal more than you realize. Least that was the problem on my 00' 1500 when I had them. Can't help but want to hear those pipes. LOL

TooTall1 Enthusiast

TooTall1

Posted
Posted

Do you have a crossover pipe on your duals? If not that actually could be part of the problem.

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