I was on an online tire site today looking for replacement tires. I typed in my M/M/Y 2008 Ford F150 XL Regular Cab 2wd and it said I have two OE sizes to choose from for my vehicle.

• Original Equipment Wheel Diameter: 17"
  
  235/70-17
  

AND

• Original Equipment Wheel Diameter: 17"
  
  255/65-17

I would like to run the narrower, higher profile 235/70-17 tire as I live in a mountainous area that gets a lot of snow and ice, but I currently have the wider, lower profile 255/65-17s on my truck.

If I were to choose the narrower OE 235/70-17 option, would that mean I would have to get smaller sized tire rims to fit them?

 

No, either size will fit fine on the stock rims.

 

no, your stock rims will fit fine. I've run 235/70-17, 245/70-17 and 265/70-17 all on the same stock rim.

Most of the 2wd xl's came with 235/70/17. Such a tiny, funny looking tire though.

Did your truck come new with the 255/65-17s?

 

Yes, the truck was fitted with 255/65-17 Hankook DynaPros. They were decent tires, a little too squishy and lacking in cornering response in my opinion.

I've not seen the 235/70/17s in person, you say they look a little funny, how bad do they look exactly?

I have the wider 255/65-17 Michelin LTX M/S2s on right now, they are a great tire in terms of mud/snow traction and highway noise/comfort. Only problem is they are suffering from sidewall cracking that is borderline dry rot. A common problem with these Michelins LTXs from what I have heard.

Michelin swears it's only "cosmetic" and I have read from lots of people that while their LTX M/S2s do have the sidewall cracking they are running strong after 50K+ miles.

Anyway, I was thinking the small funny looking 235/70/17s might be better for snow/ice handling, what's your feeling on that? They are a bit cheaper too, always a plus but if they are going to look "funny" I might just have to change my mind, lol.

 

Both the 235/70-17 and the 255/65-17 are 30" tires and will look about the same. The 255's just have a slightly wider footprint. I just meant, they're small in general from the factory and look tiny.

However, you'll get the best mpg.

You may also want to consider a 245/70-17, only 1/2 (30.6" tire) larger and there are way more options in that size. Plus, it's a very common size making the price even lower.

 

Thanks for the heads up, 2008_XL. I feel a lot better about buying a new set of tires now.

 

You're welcome. Years ago I went from the 235/70-17 up to a 245/70-17. They were great. Then went to the 265/70-17. Now back with a 245/70-17.

Heres the 245s on my truck. Also a 2wd xl.

 

Doesn't look bad at all. Is it me or is there a lot more space between the top of the wheel well and the 245/70-17 as opposed to the 255/65/17s? I would think that there would be less space with the 245/70-17s as the sidewall height is just slightly larger. Am I imagining that, or is that the really the case?

Also, online tire sites say that a larger sidewall, say 70 versus 65 will be more comfortable than a smaller sidewall, do you know if that is true or not?

 

My truck has 2.5" blocks in the rear, making it 2.5" taller. The coilovers I have in the front also lifted me 1/2". My truck is similar in height to a stock 4x4. They run a little taller.

And generally a taller sidewall will be more comfortable. The 235 and 255 will have the same size sidewal while the 245 will be slightly taller.

 

Good to know my eyes aren't playing tricks on me. Good point about the 245s being slightly taller, is that because the sidewall to width ratio?

And as you said, I just looked up the tire I am interested in getting:


and the 245 is indeed cheaper than the 235 but only by a buck or two. Kelly Tires are a subsidiary of Goodyear Tires btw. Now, you are certain these 245s will fit on the stock rims? I'm just a bit hesitant to venture outside the recommended OEM size recommendations because everything I have read says that the manufacture chooses those sizes based on tests and best results. Thus I was only inclined to buy the 235s or 255s.

I've also read that putting the wrong size tires on your vehicle can make the engine work harder than if you were to just run the OE recommended sizes. Being that I'm not an expert I have no real knowledge to back any of that up. I just want to do right by the truck.

 

Yes. 235 would by the aspect ratio and the 70 would equal 70% of that. Meaning, the sidewall is 70% of the width of how wide the tire is. That's why a 235/70 and a 255/65 would have the same sidewall. The 235 is 70% sidewall of a thinner tire, while the 255 is 65% sidewall of a thicker tire. It's hard to wrap you're head around at first. But one day I just got it and finally understood what tire sizes mean. When it clicks, you'll realize all the sizes were speaking of will fit and will not cause an issue.

245s will absolutely fit stock rims. I had 265/70-17s on my stock rims at one point. You could even fit a 285.

The very slight increase from your 255/65/17 to a 245/70-17 will not be enough to work the engine or transmission harder. Going up 1/2 will actually also make your speedometer read the exact speed you're going as appears to 3 mph faster as they're programmed.

 

Also, not many around here run that tire. I love the Firestone destination AT. Good price, lasts a long time, great in snow and they are the quietest AT tire I've ever heard. Ive had two sets of them along with a set of cooper discoverer AT3's that I didn't like as much.

Check out the firestones on tirerack. They are the top rated AT tire and are priced right around those you linked.

 

I will do just that. Thanks again for all the help.

 

No problem. Let us know what you end up doing and post pics when you do so.

 

I don't have a digital camera but I will see what I can do. It will be a while as I am going to try to get as much as I can out of these Michelin LTXs as I can. Take care, 2008_XL.