slightly bigger tires=super bad gas mileage?

[Frenchy]

I go from 24 average to 18 average switching to my winter tires and rims, 18 pounds difference at each corner. I dunno bout you but here the winter gas has more ethanol in it too, so thats a loss.

[randomhero]

Like many have said, it's not just the issue of larger tires.

It is likely a cause of many different factors. Here are some possible contributing factors:

-Decrease in temperature. The colder it gets, the longer it takes for the engine to warm up causing more fuel to be burned
-Increase in tire size and rotating mass. Likely caused about a 1 mpg loss
-Bad gas. Did you fill up at walmart or other cheap gas station?
-driving habits. You may drive the same roads to work or school, but if there is traffic, or you were in a hurry, it could have a big affect on gas mileage.

How long did you log your gas mileage? If it was less than 2-300 miles then I wouldn't say that it it's a valid decrease just yet.

[txarkitekt]

This will cause a noticeable decrease in mpg, especially if your mileage is based on around-town driving and not highway miles. Colder air requires richer fuel mixtures, and it takes longer before the engine achieves closed-loop mode, where the O2 sensor controls the air/fuel ratio. Depending on your type of driving , 4+ mpg decrease is not unreasonable.

Well said Sir.

[tatersalad25]

When I switched over from factory sized tires (cant remember what size exactly) to some really hevy BFG Mud Terrains 287/75/16 and they weigh a ton my mileage went from 19 to about 15 on the highway so I feel ya man... especially since premium is hoovering around 4 bucks

[pl4yboy]

When I switched over from factory sized tires (cant remember what size exactly) to some really hevy BFG Mud Terrains 287/75/16 and they weigh a ton my mileage went from 19 to about 15 on the highway so I feel ya man... especially since premium is hoovering around 4 bucks

I would venture to say this guy got it figured out over a year and a half ago.