Hey guys, I bought a set of concept one -RS-8 wheels. I have a 2006 is250 AWD

19x8.5 +35 (front)
19x10.5 + 45 (rear)

After looking on the forums and doing plenty of research i bought:

225/35R19 Hankook Ventus V12 (front)

265/30R19 Hankook Ventus V12 (rear)

Although the 265 have the closest diameter (which i need for AWD) they stretch quite a bit and the tire shop refused to do it. Even 275's technically only go to 10"s and would be considering stretch, (although it would be a much more milder stretch) 285/30/19 apparently is the correct size and is "square" with the rim, but differs in the rolling diameter more than the 275's. The 265 are too much of a risk in stretching because roads in wisconsin is like driving with craters. So I am stuck in a pickle.

10/10 tire calculator says the fronts are

225/35/19's are 0.92% rolling difference 825 revs/mile

275/30/19's are 2.09% rolling difference 816 revs/mile

285/30/19's are 2.96% rolling difference 808 revs/mile

Is it wiser to do 275 with a very mild stretch and have a closer rolling diameter, or have a flush tire (no stretch) but be further from rolling diameter?

p.s.- I am assuming when it says rolling difference it means compared to stock. (it says 0.92% too slow, and 2.09% too slow) Therefore if i get 225/35 and 275/30 THOSE two only differ by 1.1%? Am i correct in this assumption?

 

I used the 10/10 tire calculator and it says rim width it up to 9.5-10.5...am i missing something.
However, The tire guy showed me a chart and it said 265/35/19 9-10inches.

I attached an picture of the 10/10 calculator.. and i attached a picture of the chart that the tire guy gave me. On the corner it says ventus v12 k110 which are the tires i had so i think the chart may be accurate.

 

A 265/30 will fit a 10.5 wide wheel but it'll be mildly stretched. Some tire shops will refuse to install stretched tires.

My shop has a hunter touchless mounting system and it only took them very little effort with the install. Mostly just trying to align the tires on the wheel.

 

Here is the chart He gave me. Sorry for multiple posts.

 

He said there may be some shops around to do it, I guess my main concern is risk. He said it is possible to do it, but Wisconsin has rough roads ( potholes are like craters here) I guess im afraid to blow them or something. But when looking at tire sizes I couldn't seem to find any others that fit 10.5 while keeping the same rolling diameter fairly close. Do you mind if i ask you your specs, and if you have a pic?

 

I posted my car here maybe a month or so ago. I'll look it up.

I was able to fit a 275/30/20 and 265/3020 tire on my 10.5 wheel. You won't see it in the chart because the reommended tire width for a 10.5 inch wheel is at least 275/285 but it'll be too wide for our cars especially if you plan of lowering it.

 

265/30-19 will fit on a 10.5"-wide wheel. the stretch (if that) is safely within limits.

iirc, 275/30-19 is very close to 255/35-19 in terms of rolling diameter.

if a tire shop refuses to do business with you, time to take your money elsewhere.

 

The tire calculator is mostly accurate to find out the rims you can use on the tire.

For best accuracy, go to the tire manufacturer's website of the tire you're looking for and see what it said to double check. There maybe a case where the tire calculator's rim size range does not match the the manufacture said for its tire you're going to use.

 

Thanks man I appreciate it. Clublexus is my main resource for questions. Do you think I should switch to 275/30/19?...The difference is only 20$ if i return them

 

Is your car lowered or do you have plans of lowering it in the future?

If yes then keep the 265/30 so you'll have less chance of rubbing. I was able to fit a 275/30/20 tires on a 10.5 wide wheel in the rears because I have the same conservative offset as yours. I still had to shave my rear fenders a little bit though.

 

Since its an AWD it has a huge gap, im talking 5'6"s, i lowered it on tanabe and no only a 3" space or so. I attached a picture. It seems that the 10-10 tire calculation size was just an approximation and not a definitive choice. 275's are much less of a stretch, and 285 is the ideal size, and is "square" with the wheel. 285's will take up much more space and require fender rolling, which i would prefer than stretching. I know stretching looks a lot better, but is mostly used for lower cars to fit the wheel in. The only problem is 285's are further away from the same rolling diameter than the 275's. So its a catch 22. 285s fit better width wise, but not diameter wise. And 275 fit better diameter wise but not width wise. But the difference between the two is 1.1% or so, so I think it still should be fine.

 

Its just me but i rather find another shop and get the 265-30 installed. Cause having the rear tires running much slowwer than the front might ask for issues down the line. If you go with the 275-30 then you can match it up with 235-35.

 

Ah, I see what you are saying. That makes sense, (trust me it sounds better, and less hassle than returning them) but if i did 275 wouldnt it only be a 1% difference between the two. If the fronts are rolling .09% slower than stock, and rears are 2.0% slower than stock, the difference between them is only 1.1%? Or is that incorrect?

25/35/19's I have 265's in the rear which match 225/35s but they stretch too much. Im wondering if 225/35/19 and 275/30/19 are too much of a difference in rolling diameter