# Tire Sizes? Help!!!! **URL:** \ **Category:** SON240sx Automotive\ **Created:** [March 19, 2008, 12:23pm UTC](https://forums.speedlife.net/t/tire-sizes-help/113977 "2008-03-19T12:23:17Z")\ **Posts on this page:** 13\ **Page:** 1
**Author:** ![izzy\_domain](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/izzy_domain/32/5583_2.png) [@izzy\_domain](https://forums.speedlife.net/u/izzy_domain)\ **Post date:** [March 19, 2008, 12:23pm UTC](https://forums.speedlife.net/t/tire-sizes-help/113977/1 "2008-03-19T12:23:17Z")
Hey, I bought some used rims last year. I need to know how to accurately measure the rims width in order to calculate what size tires I need for this Spring. There are no tires mounted on the rims currently, and I see no stickers or information anywhere on the rims telling me the width. Can anyone help me out? ---
**Author:** ![John\_sinopoli](https://avatars.discourse-cdn.com/v4/letter/j/c6cbf5/32.png) [@John\_sinopoli](https://forums.speedlife.net/u/John_sinopoli)\ **Post date:** [March 19, 2008, 12:59pm UTC](https://forums.speedlife.net/t/tire-sizes-help/113977/2 "2008-03-19T12:59:10Z")
ya well u can measure from bottom to top to see if there 17,18,19s… of whatever and then measure how wide they are to see if there like7,8,9 inches so that u can get a measurement like 17 by 9 and from that u can determine what size tire u need like for example tire size is 245/50/17 what u have to worry about is the 245 part cuz thats the width i know theres not much explaining here but its a start ---
**Author:** ![John\_sinopoli](https://avatars.discourse-cdn.com/v4/letter/j/c6cbf5/32.png) [@John\_sinopoli](https://forums.speedlife.net/u/John_sinopoli)\ **Post date:** [March 19, 2008, 12:59pm UTC](https://forums.speedlife.net/t/tire-sizes-help/113977/3 "2008-03-19T12:59:42Z")
do u know what kind of rim it is like the make?? ---
**Author:** ![DJPyro](https://avatars.discourse-cdn.com/v4/letter/d/278dde/32.png) [@DJPyro](https://forums.speedlife.net/u/DJPyro)\ **Post date:** [March 19, 2008, 2:14pm UTC](https://forums.speedlife.net/t/tire-sizes-help/113977/4 "2008-03-19T14:14:48Z")
Post pictures, people might help narrow it down, but to measure width, measure from the INSIDE EDGE of the bead, to the INSIDE EDGE of the other side. ---
**Author:** ![John\_sinopoli](https://avatars.discourse-cdn.com/v4/letter/j/c6cbf5/32.png) [@John\_sinopoli](https://forums.speedlife.net/u/John_sinopoli)\ **Post date:** [March 19, 2008, 2:26pm UTC](https://forums.speedlife.net/t/tire-sizes-help/113977/5 "2008-03-19T14:26:22Z")
trueeee ---
**Author:** ![izzy\_domain](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/izzy_domain/32/5583_2.png) [@izzy\_domain](https://forums.speedlife.net/u/izzy_domain)\ **Post date:** [March 21, 2008, 5:13pm UTC](https://forums.speedlife.net/t/tire-sizes-help/113977/6 "2008-03-21T17:13:13Z")
Hey guys. When I bought the rims the 18’s had 215’s mounted on them. They looked like they had be stretched onto the rim. Whereas the 17’s had 205’s. They looked fine. I wonder if it was just the design of the tire, or if the 215 tires were too small for the rims. When I measured the rims width the other day I measured from each outside lip, both the 17’s and the 18’s read 8.5". I tried to measure the inside lip yesterday, but I noticed the inside lip of the rims are curved, so it’s hard for me to get an accurate reading with the tape measure. I could just buy the same tires that were originally mounted on the rims, but I would like to buy tires that look, and fit properly. So assuming both pairs of rims are the same width, then I should in theory be able to fit both 205, and 215 tires on the rims, correct? So could anyone explain to me why the 215 tires looked like the had been stretch on, if the 205 tires fit fine? If could I would buy 225’s, but I don’t want go out and get tires that won’t fit the rims… Damn I wish the previous owner had just left the stickers on rims. I hope I’ve explained this well enough! Will pictures help? Thanks alot for the help!! ---
**Author:** ![logik23](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/logik23/32/5548_2.png) [@logik23](https://forums.speedlife.net/u/logik23)\ **Post date:** [March 21, 2008, 10:18pm UTC](https://forums.speedlife.net/t/tire-sizes-help/113977/7 "2008-03-21T22:18:40Z")
get 225/40R18 and then down the road get real rims ---
**Author:** ![izzy\_domain](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/izzy_domain/32/5583_2.png) [@izzy\_domain](https://forums.speedlife.net/u/izzy_domain)\ **Post date:** [March 22, 2008, 8:06am UTC](https://forums.speedlife.net/t/tire-sizes-help/113977/8 "2008-03-22T08:06:03Z")
> [@Happy B-Day GTPWaNnaBe!!!](https://forums.speedlife.net/t/happy-b-day-gtpwannabe/16344/8): > > get 225/40R18 and then down the road get real rims I agree. I was going to get that for the 18’s as for the 17’s I think ill get 215/40/R17. That way I’m on the safe side, I know they’ll fit. ---
**Author:** ![S13GG](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/s13gg/32/5506_2.png) [@S13GG](https://forums.speedlife.net/u/S13GG)\ **Post date:** [March 23, 2008, 6:57am UTC](https://forums.speedlife.net/t/tire-sizes-help/113977/9 "2008-03-23T06:57:00Z")
rim width is measured from the inside of the lip where the tire bead sits. So your 8.5 measured on the outside likely has a 8" tire seat area ---
**Author:** ![logik23](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/logik23/32/5548_2.png) [@logik23](https://forums.speedlife.net/u/logik23)\ **Post date:** [March 23, 2008, 6:43pm UTC](https://forums.speedlife.net/t/tire-sizes-help/113977/10 "2008-03-23T18:43:27Z")
> [@On another topic](https://forums.speedlife.net/t/16232/10): > > I agree. I was going to get that for the 18’s as for the 17’s I think ill get 215/40/R17. That way I’m on the safe side, I know they’ll fit. The correct size for the 17s would be 225/45R17 or maybe 215/45R17 if you can’t find the first one. ---
**Author:** ![Kev](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/kev/32/5653_2.png) [@Kev](https://forums.speedlife.net/u/Kev)\ **Post date:** [March 23, 2008, 7:24pm UTC](https://forums.speedlife.net/t/tire-sizes-help/113977/11 "2008-03-23T19:24:56Z")
i’m assuming that these will be goin on a 240? ---
**Author:** ![Slide\_Junkie](https://avatars.discourse-cdn.com/v4/letter/s/74df32/32.png) [@Slide\_Junkie](https://forums.speedlife.net/u/Slide_Junkie)\ **Post date:** [March 23, 2008, 7:55pm UTC](https://forums.speedlife.net/t/tire-sizes-help/113977/12 "2008-03-23T19:55:46Z")
[http://www.gti-vr6.net/library/engine/Schrick\_howto/wheeldiameters.htm](http://www.gti-vr6.net/library/engine/Schrick_howto/wheeldiameters.htm) Stock size is 205 60 r 15 -42 rim Go from there ---
**Author:** ![kimmerkaze](https://avatars.discourse-cdn.com/v4/letter/k/9d8465/32.png) [@kimmerkaze](https://forums.speedlife.net/u/kimmerkaze)\ **Post date:** [March 24, 2008, 8:45pm UTC](https://forums.speedlife.net/t/tire-sizes-help/113977/13 "2008-03-24T20:45:38Z")
fyi, i usually just round the full width down to the nearest 1/2" if you want to think of it that way for wheel widths. also, depending on the fitment you’re going for, it might be nice to factor in reinforced or non-reinforce sidewalls. the beefier sidewall lip looks good for some ratios but not for all in my opinion.