225 vs. 235 Inner Clearance

[3MPSPWR]

Hi,

So after fitting my new wheels over the weekend 18X8.5 with a +45 offset. I told my mate that was fitting them that i wanted to run 235/40/R18s for my next set. We both had a look at the inner clearance and he reckons i should stick to my 225s instead as 235s MAY scrub on the struts.

I later drove the car on the highway and realised that i had the exact same vibration as i did when my stock tires were about to go. I was already told my current set wont last too long, after only driving it for about 17,000km. (Yokohama S-Drives) Car currently sits @ 37,000km.

So i'm after another set, but the problem is im not sure if i should go 235s or 225s as i'm also getting coilovers put in by Fulcrum... Not sure if that will change much?

I did have a look at the inner clearance today just felt it and it seemed like between the rims and the strut i could just fit my index finger in. So i dunno if 235s will scrub or not.

After looking at the USA forums, a few punters there are running 245s on the same setup?? Kinda confusing the hell outta me.

What does people think??

[Yeldarb]

Hey Eddie, I just popped outside and had a look at my set up.

So I have the Speedy Lite Fin, 18x7.5 Offset 45. I have 235/40/18 rubber.

So with no weight in the rear, and very little fuel, I can get my thumb in between the tyre wall and guard.



Here's another top shot looking back



If that was an 8.5 rim (inch wider right?) I would have rub city. I like the wheel recessed as it clears the guard easily. I've had 2 passengers in the back and the only noise is hitting the bump stops going over speed bumps too quickly.

[3MPSPWR]

Hey bud, yea i think u can run 235s cause ur at 7.5 inch width. Where as i gotta account for that extra width. It does sit very very flush, dont have any scrubbing issues yet but then again i haven't dropped it.. Should show ya when i drop it alittle, kinda sits like a tonka truck atm

But i can't believe i'm now buying a THIRD SET OF TIRES... What is this? MPS's chew through tires like rotary chew through motors?

[Nexus]

Hi,

So after fitting my new wheels over the weekend 18X8.5 with a +45 offset. I told my mate that was fitting them that i wanted to run 235/40/R18s for my next set. We both had a look at the inner clearance and he reckons i should stick to my 225s instead as 235s MAY scrub on the struts.

I later drove the car on the highway and realised that i had the exact same vibration as i did when my stock tires were about to go. I was already told my current set wont last too long, after only driving it for about 17,000km. (Yokohama S-Drives) Car currently sits @ 37,000km.

So i'm after another set, but the problem is im not sure if i should go 235s or 225s as i'm also getting coilovers put in by Fulcrum... Not sure if that will change much?

I did have a look at the inner clearance today just felt it and it seemed like between the rims and the strut i could just fit my index finger in. So i dunno if 235s will scrub or not.

After looking at the USA forums, a few punters there are running 245s on the same setup?? Kinda confusing the hell outta me.

What does people think??

Easy.

225 --> 235 adds 5mm either side of the tire when you compare fitment to the same rim.
If you can fit any finger in the space, well, you're finger is a good deal more than 5mm so...my bet would be a tentative ok on the inside, although what happens through the full length of suspension travel needs to be considered.

I find it hard to imagine it not rubbing on the guard though; with 225 I can just see it staying clear, maybe. With 235 my bet would be on rubbing quite a lot, even if it's not now.

---------- Post added at 10:46 PM ---------- Previous post was at 10:44 PM ----------

Actually. Even easier.
RX-8 +50 with 235/40R18 fit on the inside (struts).

Therefore you're proposed 235/40 @ +45 should be well clear of the struts. It's the gaurds you'll have to worry about.

[3MPSPWR]

Hmm.. Yeah thats what i'm not sure about, it may "seem" clear but how beneficial really is an extra 1cm on the tread? Kinda starting to think going 235 will probably have more problems.

It actually sits quite flush with the guards on a Gen 2, so i guess providing that u don't drop it too low then it should be "ok" so to speak. I dunno yet cause i haven't lowered it

Yea the RX-8 rims i dunno if theres any difference between the GT ones and the series 1 specs but i thought the rims were 8 inch wide? so i guess even with a 50+ offset it should still clear running 235s? But my wheels are 8.5 inch wide so it comes closer to the struts...

Hmmm.. Wonder anyone else run a 8.5inch?

Easy.

225 --> 235 adds 5mm either side of the tire when you compare fitment to the same rim.
If you can fit any finger in the space, well, you're finger is a good deal more than 5mm so...my bet would be a tentative ok on the inside, although what happens through the full length of suspension travel needs to be considered.

I find it hard to imagine it not rubbing on the guard though; with 225 I can just see it staying clear, maybe. With 235 my bet would be on rubbing quite a lot, even if it's not now.

---------- Post added at 10:46 PM ---------- Previous post was at 10:44 PM ----------

Actually. Even easier.
RX-8 +50 with 235/40R18 fit on the inside (struts).

Therefore you're proposed 235/40 @ +45 should be well clear of the struts. It's the gaurds you'll have to worry about.

---------- Post added at 11:33 PM ---------- Previous post was at 11:31 PM ----------

I should take some photos tomorrow, problem is u can't see the inner clearance..

---------- Post added at 11:45 PM ---------- Previous post was at 11:33 PM ----------

Actually i had some photos taken the other day when it got fitted.

Not very clear tho, gonna take more once its dropped.

[3MPSPWR]

[KFuNk]

Dont worry man! I'm running 235/40/18 on 18X8.5 +40. Trust me its gonna scrub even rolled just gotta live with it! I had full car plus 4 suitcases to the airport every bump was pretty much a scrub fun time! Fitment will be fine tho! Really no scrub if only driver and front passenger!

[Nirvandan]

Fark scrubbing.... no good for your guards or your tyres, specially if you have good rubber. Any chances you can just fit 235 for test purposes and see how you go?

I got a set of 18x8 +35 wheels with 235 rubber sitting in the garage, however the rubber is shagged and not road worthy, but they might be usefull for a test fit.

[Yeldarb]

Yes you will scrub if you go really low. I think you can drop 20mm and be ok. If you are going coilies then you can find the perfect height.

[blackbetty]

Maybe also get yourself some more user friendly tyres, you probably wont chew through them nearly as quickly. Many options out there that have good performance, grip and handling and a decent wear rating at the same time

[naasif]

Excuse my ignorance...but can you run 235/40/18 on the 18x7.5 rim (which is stock GEN II rim) ?

All the tyres I've been looking at on tirerack says the 235/40/18 needs a min 8" rim. Will this cause uneven wear or fitment issues with the wider tyre on the narrow rim ? Or does the extra 10ml width not really make a difference.

The 225/40/18 (stock GenII) tyre fit on a min 7.5" rim.

[RadiantKnackers]

At stock ride height you should be able to run 235/40's on an 8.5" rim of +45 offset without much issue.

If you are lowering considerably, then you would probably have to drop back to 225/40 to avoid the scrub monster.

I have 8.5" +40 rims going on my car, but after some playing around with tyre sizes, I have had to ditch my idea for 245/40 rubber and settle for 235/40 tyres.

If I decide to lower at some stage will probably drop back to 225/40's.

[Nexus]

Excuse my ignorance...but can you run 235/40/18 on the 18x7.5 rim (which is stock GEN II rim) ?

All the tyres I've been looking at on tirerack says the 235/40/18 needs a min 8" rim. Will this cause uneven wear or fitment issues with the wider tyre on the narrow rim ? Or does the extra 10ml width not really make a difference.

The 225/40/18 (stock GenII) tyre fit on a min 7.5" rim.

You're absolutely right. 99% of 235/40 specify an 8" rim. That specification is what decides if you have a warrantable, roadworthy fitment. If you are going to fir 235/40 to 7.5" rims, choose your tyre very carefully so it is within spec is my advice.

I expect it would show only trivial differences in terms of wear.

[Caffeine Fiend]

I'm fairly certain Linda (Leelu) has been running 235 Kumho tyres on her stock rims for a while now

Just FWIW


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[player1]

i am in a similar situation, got some 18x8 rims that i want but with offset of +55, i also want to put some 235 instead of 225, just dont think they gonna fit.
is there legal and safe spacers for the rims???? to make sure enough inner clearance, also filling the guards bit more for a better look???

[Caffeine Fiend]

I know in Vic spacers are illegal for road use

Don't know about NSW though


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[blackbetty]

I wouldnt think 18x8 +55 with 235 is going to give you any problems at all.

Besdies you dont want spacers which are illegal and dangerous

[Reedy]

Dont worry man! I'm running 235/40/18 on 18X8.5 +40. Trust me its gonna scrub even rolled just gotta live with it! I had full car plus 4 suitcases to the airport every bump was pretty much a scrub fun time! Fitment will be fine tho! Really no scrub if only driver and front passenger!

Just gotta live with it? What? How about you don't get wheels and tyres that rub because that shit is ****ing stupid.

[KFuNk]

Just gotta live with it? What? How about you don't get wheels and tyres that rub because that shit is ****ing stupid.

Not Stupid don't know till you try maybe extended the truth a little but Edwin wanted my honest opinion so I gave it! Gives him and whoever wants to do it a better understanding on which path he'll take...! My car ain't a family wagon never will be!

[MUZZA]

Just to weigh in here with my current setup...


- RX-8 [SE3P] 18x8" +50 offset
+
- 235/40 tyres
+
- lowered springs


= No rubbing.