Tire size and mileage question

[MtPaul401]

I have 315 75/R16 on my rig now but will be putting 265's on soon, another set of all terrain type tires like I have now. I'm getting around 16.5 city now, 17.5 to 18.5 hwy. What kind of mileage increase, if any, can I expect on the smaller stock size tires?

Thanks!

[AYP Tires]

I would imagine you will notice a nice difference. It's hard to say exaclty but 2mpg is a good estimate. They will weigh in 16lbs lighter and about 3" less in height. They might look a little goofy though since you are used to the 315's

[strokin_early_99]

I was getting 20mpg with my stock tires. It dropped to 18.5mpg when I put on the 315's.