255/75/17 or 265/70/17

[Nashvillerunner]

Alright guys it is that time for me to purchase tires. I can't decide on the 255/75/17 or the 265/70/17. Is there really much difference from the eye that you can notice about these tires. I know the 255 is a tad skinnier than the 265 but I can't really tell by pics if there is that much of a difference.

In your opinion what are the pros and cons going with the 255/75/17 and the 265/70/17. I have done my research and searched here but just wanting your opinions on each size.

I have the FJC spring and shock lift with the Toytec 1" spacer up front.

 

[chaz]

heres an example of size difference on GYSA, depending on what brand & type of tire u get , the height & width difference is small, eyeing them up, side by side is pretty much unnoticable, IMO. example: GYSA 255/75 is 43lb. 32.1, & 10 sw, tread w 7 265/70 is 48lb. 31.7 & 10.7 sw, 8 tw. the biggest thing is the 5lb more per tire, so a very slight hit in mpg... for me, i would prefer the 1 in. more tread width for the street. but to each his own. go to tirerack & compare the sizes of the tires u want.

 

[gaterose]

I wanted the 255 for the extra 0.4" of height and supposed mpg savings, but there aren't a lot of tires in that size. Almost all A/Ts and M/Ts come in 265 but I could only find about 10 that came in 255.

Another thing I wanted was white letters and the only 255 (that I could find after extensive search) with whites are the bridgestone revo2 (LT) & firestone a/t. I have a lot of experience with BFG and I went with 265 because they don't make a 255 A/T (although if you want M/T they have that in 255 & it's a great tire).

If you want one of the brands that makes a 255, and want blackwalls, I personally would get 255. Just my 2 cents

 

[Nashvillerunner]

I wanted the 255 for the extra 0.4" of height and supposed mpg savings, but there aren't a lot of tires in that size. Almost all A/Ts and M/Ts come in 265 but I could only find about 10 that came in 255.

Another thing I wanted was white letters and the only 255 (that I could find after extensive search) with whites are the bridgestone revo2 (LT) & firestone a/t. I have a lot of experience with BFG and I went with 265 because they don't make a 255 A/T (although if you want M/T they have that in 255 & it's a great tire).

If you want one of the brands that makes a 255, and want blackwalls, I personally would get 255. Just my 2 cents

Thanks man! Have you noticed a loss in MPG?

 

[ARK_SWAMP_RIDER]

255/75/17 IMO, although the difference is marginal. The biggest deal to me was that the 255/75's actually increase mpg, and 265/70 decrease it slightly. See the link in my sig for pics of mine, pretty much same setup as yours except stock rear.

 

[JCR]

255/75/17 IMO, although the difference is marginal. The biggest deal to me was that the 255/75's actually increase mpg, and 265/70 decrease it slightly. See the link in my sig for pics of mine, pretty much same setup as yours except stock rear.

Just a note: I lost over 2mpg's(edit: more like 1.5 after looking back) with 255/75 and thats calculating the difference in tire size. I did add a 2/1 lift but I doubt that dropped my mpg's that much alone. I wish I would have gone with 265/70 due to more tires available and IMO the width is noticable and doesn't look near as good. Next time it will be 275 though.

 

[ARK_SWAMP_RIDER]

I beg to differ. I've known of quite a few members who have switched to 255/75/17's with either no loss or an improvement in mpg. I can't say I've heard of anyone loosing mpg from just tires alone (you'd be the first). I did thorough research before selecting the 255/75's, and a loss in mpg never came up. Do you have the Dynapro ATM's, or one of the MT's?

That said, let me clarify on it being "noticeable". When I switched, I don't notice it being much if any different that before. I went from stock 265/65 to the 255/75, so of course height was very noticeable, but I'd guess to say the difference between 255/75 and 265/70 wouldn't be. However, when I park next to a buddy with a 4th Gen and 265/70's, I can visually see a difference side by side in width. I'm sure every one of us has a different definition of "noticeable", so I'm not saying your wrong and I'm right, or vice versa. Just from my experience, I didn't notice the difference in width when I made the switch.

 

[chaz]

there are a few others that have reported a loss of mpg with the 255 also, scroll down to mathewy03 's post, it is one i found quickly, & i bet theres more. http://www.toyota-4runner.org/perfo...nother-new-tire-thread-narrowed-way-down.html here a decent calulator showing differences in size. http://www.tacomaworld.com/forum/tirecalc.php

 

[gaterose]

Thanks man! Have you noticed a loss in MPG?

Yes, about 0.5-1 mpg depending on driving conditions. Some of that is also due to the more aggressive tread over the dueler H/Ls I'm sure.

255/75/17 IMO, although the difference is marginal. The biggest deal to me was that the 255/75's actually increase mpg, and 265/70 decrease it slightly. See the link in my sig for pics of mine, pretty much same setup as yours except stock rear.

are you certain its an improvement and not due to the tire being taller and changing the speedo/odo slightly along with getting the same actual mpg? At 45 mph, you're really doing a little over 47.2, that adds 47.2 miles to odo for ever 45 you travel (right?). So if you travel 380 miles, the 4runner thinks you've gone closer to 400. At higher speeds it increases even more.

I just can't understand how less than 1/2" of width (rolling resistance) can more than offset 1-1/2" of diameter as far as mpg goes. Especially considering how much 1" of diameter with no change in width decreased my mpg.

 

[Nashvillerunner]

Not to sound dumb just a little confused but which width are you talking about? The Tread Width, Section Width or Rim Width?

 

[matthewy03]

I know I lost 2 MPG when switching from the stock bridgestone 265/65 to the GYSA 255/75 tire. Difference being I know ARK_SWAMP has the V8, where I only have the V6. But I KNOW that I lost milage, even when factoring in the overall diameter of the tire is larger.

 

[ARK_SWAMP_RIDER]

Chaz, idk then, it's the first I remember hearing about.

gaterose-your threory works, but I think it is to my advantage (if I'm thinking right). I'm always hand calculating mpg, I don't rely on the display. My odometer will read slow, so I've went further than it says. So, if I read 380 miles over say 20 gallons of gas to make things easier, 380/20=19. Well, I actually went ~400 miles, so the adjusted reading would be 400/20=20. So, just by figuring in odometer error, you can see a 1 mpg difference in this case. Come to think of it, this may be why some say they see a .5-1 mpg loss with both sizes. I typically don't consider odometer error, and even when I don't my mpg is still up (yes it is slightly, maybe .5, but it's not a loss). So, when I do account for odometer error, I'm actually at around 1 mpg above what I had before.

The main thing I see is in most cases the 255/75 is 6-8 pounds lighter per tire (than 265/70), which adds up. Also, the narrower width makes less resistance, so it's easier to get moving (and keep moving once started).

I may be way off here, but that's just the way I see it.

matthewy03-That is indeed odd, kinda making me put my foot in my mouth after saying I've not seen anyone lose mileage. I do have the v8 which *could* make a difference, but I know others with a v6 had similar results as mine, CJ3FLYR is one for instance. See his thread here.

For those who are saying loss of gas mileage: did you lift or make any other changes at the same time? I did my lift, then tires a few weeks later after getting a couple tanks ran through for testing. No real difference in my case before/after lift, but I also only did 1.5" lift in the front.

 

[JCR]

I have the 255/75/17 in the Dynapro ATM 33-35psi. I'm not going by the computer even though it went down about .7 after the change. I added a toytec 2.5/1.5 lift and tires within a couple days of each other. City driving I'm down actually about 1.5 and highway is about the same, maybe 1 or so. (edit) I am adding 5% to what my odo says which should account for the tire size difference.

Ark_swamp_rider, what kind of tires did you have before the change? What kind of pressure were you keeping? It's possible you were just getting crappy mpg's before and new tires alone improved it. Just a thought.

By the way, I drive like a grandma so driving habits did not change.

 

[chaz]

gaterose brought up a good point, the brand of tire & tread design someone has now & the brand they're switching to may help to account for different mpg besides the size.

 

[gaterose]

Nash, we're talking about tread width, that's what makes contact with the ground and is the supposed cause of the increase in mpg (less rolling resistance).

ARK your odometer will actually read fast, as I said for every 45 miles you travel, it will think you've traveled 47.2, so when your odo thinks you've traveled 400, you've really only traveled 380. Not the other way.

Chaz, thanks, tread design it has to make some difference I noticed a difference on my last truck switching from 285 ATs to 285 MTs. the Dueler H/L to BFG AT may not be as drastic of a change but it has to have some effect

 

[matthewy03]

Nash, we're talking about tread width, that's what makes contact with the ground and is the supposed cause of the increase in mpg (less rolling resistance).

ARK your odometer will actually read fast, as I said for every 45 miles you travel, it will think you've traveled 47.2, so when your odo thinks you've traveled 400, you've really only traveled 380. Not the other way.

Chaz, thanks, tread design it has to make some difference I noticed a difference on my last truck switching from 285 ATs to 285 MTs. the Dueler H/L to BFG AT may not be as drastic of a change but it has to have some effect

Gaterose,

Ark is right with the Odometer reading. If you think about it when you put on a larger diameter tire than what was on before ( meaning also larger circumference ), for every one turn of the tire, you will be going a longer distance than you would have before correct?? but the computer doesn't know this, so your speedometer and odometer will both be behind a little. This is why when at least on mine, my speedometer reads 65, when i am really going 67.

 

[ARK_SWAMP_RIDER]

See this calculator for info on speedometer differences, Tire Size Calculator - Compare Tire Sizes. I had stock size bridgestone dueler hts before the hankooks.

 

[4Beast]

Well, I seldom get tired of these threads about tires. I keep wondering whether the V6 vs. V8 has an impact on whether there is a mileage decrease. It just seems like the V8s shouldn't struggle to roll over a heavier tire, and would therefor use less fuel to do so. Or alternately, maybe their milage is slightly lower anyway, so there is a little less room for small changes to make an impact? I have decided to get 255s when i get new tires (prob in a few weeks) in slight part because of the milage, but also due to less chance of rubbing on suspension parts with no lift (yet). At the risk of a total thread jack, does anyone think that 255 MTs, (like the BFG) would fit with a stock suspension setup? i figured no, with the extra tread depth and knobbier tread.

 

[chaz]

id say if ur going from an all season or AT tire to an MT the mpg would go down because of the tread design & not up because of the 255. heres the 255 MT, http://www.toyota-4runner.org/4th-gen-t4rs/46799-32-bfg-m-t-installed-no-lift-pics.html

 

[gaterose]

Gaterose,

Ark is right with the Odometer reading. If you think about it when you put on a larger diameter tire than what was on before ( meaning also larger circumference ), for every one turn of the tire, you will be going a longer distance than you would have before correct?? but the computer doesn't know this, so your speedometer and odometer will both be behind a little. This is why when at least on mine, my speedometer reads 65, when i am really going 67.

Yeah you guys are right sorry.. I was doing the math backwards.