Tire Size

[SilverI30]

Hi guys, i was thinking about purchasing some rims for my 1997 I30, but the size of the tire is 245/40/18......i dont know where but i recall that 235 is the highest size i can go up to for that model, now is that true?? I need some feedback plz.Thanks

[maxhopper]

245 is the width of the tire in millimeters. I'm no tire guru, but I think it depends on the offset of the wheel. Here is a link that may be helpful.

I'll leave this here for a while and see if anyone more knowledgable than myself on the issue posts. If not I will move this thread to the tire/wheel forum.

[SilverI30]

i am a bit clueless, when u say offset what do you mean?

[maxhopper]

How far the wheel sticks out.

[audtatious]

Offset is:



245 is too wide for a 7" rim. 235 would be the widest I would trust, but even that is too-wide for spec...

[SilverI30]

ahhh ok, where can i obtain this information?

[SilverI30]

Offset is:



245 is too wide for a 7" rim. 235 would be the widest I would trust, but even that is too-wide for spec...

what do you mean 7" rim? the rims i want to get are 18"...

[maxhopper]

The width.

Thanks Matt!

[audtatious]

The width.

Thanks Matt!

If you are getting 18" rims, they should be a minimum of 7.5". You can run 245's with these without any problems. I would suggest a 40mm offset and I would also suggest a set of 10mm spacers for the rear as well. 30mm offset is the lowest you can go (30mm will make the back rims fit great, but the front rims will look like they stick way out).

[SilverI30]

If you are getting 18" rims, they should be a minimum of 7.5". You can run 245's with these without any problems. I would suggest a 40mm offset and I would also suggest a set of 10mm spacers for the rear as well. 30mm offset is the lowest you can go (30mm will make the back rims fit great, but the front rims will look like they stick way out).

40mm offset i sorta understand, what is the 7.5" referring too?what is a 10mm spacer? so you saying 30mm for the back and 40 for the front....but who adjusts this? the shop?

[maxhopper]

40mm offset i sorta understand, what is the 7.5" referring too?what is a 10mm spacer? so you saying 30mm for the back and 40 for the front....but who adjusts this? the shop?

7.5 in the width of the wheel in inches.

This is a wheel spacer.

The offset of the wheel is what it is. This can not be changed, it is just how the wheel is made.

[audtatious]

All four wheels would have a 40mm offset. The 10mm spacer would be on the back (= 30mm offset with spacer). When you have the shop rotate tires, they simply leave the 10mm spacer on the back.

[SilverI30]

7.5 in the width of the wheel in inches.

This is a wheel spacer.

The offset of the wheel is what it is. This can not be changed, it is just how the wheel is made.

ahhhh i c, so your saying 30mm for the back with a 10mm spacer???

and the front 40mmoffset? why not just make the front and back 40mm so there would be no spacer needed.

or am i not understanding it completely.??

[SilverI30]

All four wheels would have a 40mm offset. The 10mm spacer would be on the back (= 30mm offset with spacer). When you have the shop rotate tires, they simply leave the 10mm spacer on the back.

is it safe to assume that it is at 0 right now and i want them to be at 40mm? and a 10mm spacer for the back..

how do i get the 40mm offset, thats my question i guess.....

and where can i get the spacer?

sorry for all the annoying questions

[audtatious]

Anything <30mm offset would cause the tire to scrub the inner fender, so you don't want to get a rim with an offset lower than that. Per my picture:



You will see two offsets, 45mm and 35mm. Offset is the distance from the mounting hub of the rim to the exact center of the rim. 35mm means the mounting section of the rim is 35mm from the center of the rim. The black curved portion of the image represents the fender. Below shows offset in detail



The lower the mm, the less amount of offset from the rims center section. The lower the offset, the higher amount of rim width extends out from the hub.

If you went outside and looked at your car from the back, at an angle where you can see the rear and front rims and wheel wells, you will notice that the back rims seem to be set deeper into the wheel well than the fronts which makes the front wheels look like they stick out further. The factory offset is 45mm. You can make the back end better by replacing them with rims that have a 35mm offset, since more of the rim will extend outward. Of course, after doing this, you could never rotate the back rims to the front of the car. If you replace all rims with 35mm offsets, the back rims look better, but the front rims now stick out even further. To get around this whole issue, you could get 45mm rims and use 15mm spacers (or more common 40mm offset rims with 10mm spacers). The spacers would be on the back to help resolve that "set in" look.

[SilverI30]

ok, im beginning to understand this a little bit better, now how do i know the offset of the rims i plan on purchasing?

[audtatious]

They should say what the offset is or you may be able to select the offset you want. Depends on the rim manufacturer and what they make... Again, I suggest a 40-45mm offset and a set of spacers for the back. If you go with 45mm and opt for 15mm rear spacers, you will need new studs that are longer. 40mm w/10mm spacer does not need new studs from what I have seen.

[SilverI30]

They should say what the offset is or you may be able to select the offset you want. Depends on the rim manufacturer and what they make... Again, I suggest a 40-45mm offset and a set of spacers for the back. If you go with 45mm and opt for 15mm rear spacers, you will need new studs that are longer. 40mm w/10mm spacer does not need new studs from what I have seen.

thanks for your help bro.

[audtatious]

thanks for your help bro.

No problem. Good luck and make sure you post some pix here!

[SilverI30]

will do! but it might come after the winter, but i have pics of the rims if your interested.

[audtatious]

Sure, post'em up.

As soon as my tires go out, I will probably downgrade back to my 17's. Need a more comfy ride..

[SilverI30]

the 18's really make that much of a difference? hrm perhaps i should reconsider, cause i have to drive atleast 60 miles aday to school. and if i start working that will increase to about 100+ a day

p.s. NOT my car, thats the sellers car.

[audtatious]

I was actually looking at that style of rim, but could not find them local when I needed them.

18's with 40 series tires are very rough when you throw in an aftermarket suspension. I have bent 3 so far due to bad roads.

[SilverI30]

hrm i wasnt even thinking about the suspension.....just going to leave it stock for now....until i have more money.

rim/tire specs... Zenetti Vega 18x8.5 Chrome Rims Toyo FZ4 245/40/zR18

speaking of roads, im from nyc, the roads are HORRIBLE!!!!!!! but im in philly right now so its not that bad here.....oh did i mention one of the rims is bent? ill have to also get that fixed later on

[SilverI30]

......

[audtatious]

Ow. That looks painful.

Mine are not bent like that, they are actually warped.

[SilverI30]

yeah he says it holds air and can be fixed for about 100 bucks..

[audtatious]

I would validate. Also check ebay to see if you can find a new or used one for around that price. I'd rather have one that has not been bent before.

[SilverI30]

good idea, ill check it out.

[SilverI30]

not the best pics....but its better than nothing