Hey guys,
recently purchased an 08 suburban and my avg economy always says 12.0, no matter how much the Inst economy fluctuates when I’m on mostly highway trips, etc. wondering if this is a common problem or have any idea why this would be happening. Thanks!

Zach R
08’ Suburban LTw/LT3 Z71
5.3L FF

 

I've owned a number of pickup trucks over the years, as well as an old Jeep CJ-5. The mileage doesn't tend to vary that much in a heavy duty vehicle, particularly if the axle ratio is high, like 3.73-4.10 gears and its a four-wheel drive as well. Never owned a Suburban style vehicle, but I believe it's based on a pickup ladder frame.

I assume the FF means Flex Fuel, which I have never owned. I have always heard that they get horrible gas mileage compared to a gasoline or diesel engine.