is there a big size difference between these two tires?

 

Do some checking here. http://www.1010tires.com/TireSizeCalculator.asp

I went from 255/65/17 to 265/70/17. About an 1 1/2 diff in heigth. fills wheel well much better.

 

i have pics of my truck with 255/70/16's in my gallery and a pic with 265/75/16 in my sig. mac

 

Yeah, we can't tell you the difference in size without the entire size. All we know for sure is the 265's will be 10mm wider.

 

No there is not a big difference. I went from 255 to 265. Was not big enough so now I am at 285 and those are what you need. Big Meats

 

There is a big difference between 255/35R17 and 265/70R17. There is not a big difference between 255/70R17 and 265/60R17.

As Wandel pointed out, we need to know the whole tire size.

 

I went from OEM 255/70/16 to 265/70/16 and noticed a drop in gas mileage but, everything was a lot closer, work,store,etc.. so it was a wash.

 

Hehe

 

The only difference between a 255 and a 265, like Wandell said, the tire is going to be 10mm wider. If you want a taller tire you need to look and see if it is a 55, 60, or 65 and that is where you get taller... Damn metric conversions...

 

FWIW, when I went from 255/70/16 to 265/70/16 on my '99 4.2 SC with automatic and 3.55 gears, I noticed a drop in performance with the wider, taller, stickier tires. I thought I would get better mpg with the taller tires, but I did not.

So worse performance, same mileage, slightly better looks and ground clearance.

 

Im sorry, that is what I meant, 255/70/16 and 265/70/16

 

most people think that there gas mileage drops putting a bigger tire on but my truck with 265's gets about the same. What you dont think about is when you get bigger tires you oedometer will be off! When we went on a road tip with our car and truck the truck was around 30+ miles low! Going off the truck miles for mpg i was like this sucks around 10mpg! But it redid it with the miles from the car and it was around 18mpg so i was happy!! Just to give you and idea! So everytime people get bigger tires and you dont get your oedometer reset it will seem you lost some gas mileage I think my oedometer is about 8-10mph off!

 

Wow! I'd like to see your math on that!

My 3.5% larger tires get 15% lower fuel economy than stock. There is not way you changed your tire size by 80% to make up for 10mpg to 18mpg difference in calculations.

Going form a 32" tire (typical stock 4WD size) to a 35" afftermarket tire will mean you are travelling 9.4% further than your odometer says, uncorrected. Let's say 10% more than 300 miles per tank and you put in 25 gallons. That's the difference between 12mpg and 13.2mpg, exactly the 10% better fuel economy. It's nothing like 80% of 10-18mpg. My example, 32" tires to 33" tires is "only 3% larger", but cost me about 2mpg, from 14 average to 12 average.

it still depends on how one drives as to how fuel economy is affected.