Need a bit of help with tire sizing please
 

Ok so i have been using the tire calculator for a bit now and have a question that someone who knows more than me about tires might be able to answer.

So after trying on my friends advan rs wheels i decided to opt for these instead of the volk gts.

After using the offset calculator and seeing someone else on the forums with them im going with the

19x9 +38 offset in gunmetal gray! =D

So now after using the tire calculator i am a bit confused.

using the stock tire size of

225/45/18
Overall diam. 25.97
rim width range 7-8.5

I tried 3 different sizes

245/35/19
Overall diam. 25.75 in
rim width range 8 - 9.5 in
speedometer difference 0.849% too fast

255/35/19
Overall diam. 26.02 in
rim width range 9.5 - 10 in
speedometer difference 0.200% too slow

265/35/19
Overall diam. 25.97
rim width range 9 - 10.5 in
speedometer difference 1.277% too slow

So according to this the closest to stock would be the 255/35/19 but why is the rim width go to 9.5-10 for the 255 then back down to 9-10.5 on the 265s?

Can anyone explain this please because i am so confused.

Hmm, when I was looking at tires I was told that 255's were not wide enough to suit 9.5. So I went 275's :lol2:

Might possibly be down to the individual manufactures. Are all the sizes you mentioned about from the same manufacturer?

255/35/19 will fit an 8.5-10.0 rim according to toyo's website

I got Toyo's :Eyecrazy: :)

Is it a case of what's possible as opposed to what is recommended?

There must be implications on tire wear depending on the combination you end up with?

I am sure the wheel guru's on here will be able to provide some info...

Either the 245 or the 255 should work very well on your wheels. Remember, your tires are typically molded with 10/32" tread depth and are illegal at 2/32" tread depth, so every tire normally loses 1/2" of overall diameter over the course of its service life. Geeking out and stressing over diamater differences less than that is for geeks without cool hobbies.

My rule of thumb is to use a rim width 0.5" less than the maximum recommended width by the tire manufacturer whenever possible, so of the two, I'd likely pick 245 for the 9" wheel.

On the other hand, I'd go with 18s or even 17s, so don't listen to me.

thanks for the help i was just using the tire calculator as a base since im not 100%

a 9 inch rim will work perfectly fine with a 255/35/19 tire