Quick Question, First Post

[Gag-3]

Just put some BFG a/t's on my 07 crew cab 1500 4x4. The factory tire lasted 69k miles and average 16.9 to 17.1 mpg. Had the new tires for 500 miles and I am struggling to get 15 mpg. Is this normal, should I expect this big of a decrease? The tire dealer that I purchased these from is shocked at the change. I currently have 45 psi in each tire...would a decrease in pressure benefit me in any way. Thanks in advance.

[cc1999]

Ya, that happens sometimes. GM is notoriuse for using light weight low ristance tires to pump up there EPA MPG ratngs. My Z71 Suburban gets less mileage than some regular Suburbans, I am sure its got something to do with the 18s and the AT tires.

 

I was getting as much as 17 with the oem goodyears on my Ram, I put some new silent armors on it a couple months back, I am lucky to get 15 now.

[06pirate]

I had the same thing happen. Recently replaced the OEM 20" Goodyears with 17" Les Schwab Open Countries ( which worked surprisingly well in the recent snow) and my mileage went from 19.2 average down to 16.8 (2006 GMC Sierra X-cab 4x4 SLT, 5.3L). Pissed me off.

[Silverado4x4]

Alot depends on the tread design as a more aggresive tread creates more rolling resistance and the truck has to work a little harder to push the tires. Factory tires are more of a highway tread with less rolling resistance.

[pennzoil29]

While I'll agree that different tread tires can cause a change in fuel mileage, you have to remember, some of us, if not all, are running winter blend fuel now. I lose on average 2-4 miles a gallon during the winter month's.

[builderpaul]

Just put some BFG a/t's on my 07 crew cab 1500 4x4. The factory tire lasted 69k miles and average 16.9 to 17.1 mpg. Had the new tires for 500 miles and I am struggling to get 15 mpg. Is this normal, should I expect this big of a decrease? The tire dealer that I purchased these from is shocked at the change. I currently have 45 psi in each tire...would a decrease in pressure benefit me in any way. Thanks in advance.

 

Same size new tires as old, right?

Decrease pressure will usually give less mpg but better ride.

[Silverado4x4]

While I'll agree that different tread tires can cause a change in fuel mileage, you have to remember, some of us, if not all, are running winter blend fuel now. I lose on average 2-4 miles a gallon during the winter month's.

 

Good point Jeff I forgot about that one.

[geektoad]

Winter gas might account for it, but depending on the load range of the BFGs, you probably just added around 10 pounds per tire going from the P series, non-load rated tires from the factory to a C or D load range tire. Adding rotating mass will effect your mileage an order of magnitude more than non-rotating mass (like something in your bed). That 40 pounds of rotating mass is like driving around with 400 pounds in the bed of the truck as far as the drivetrain is concerned.

 

See Scott's quote in my sig....