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[Gangplank]

I've been reading through apex and vmr threads and I'm wondering why all the wheels are 18x8.5 et45 and then everyone says to run a 3-5mm spacer to make a 245/30 fit.


So why doesn't anyone make wheels in either

18x8.5 et40 or et42

18x8 et45

Seems they would work better? Or what am I missing?

[Fume]

One reason might be to allow people to run square setup using 18x8.5 et45 with spacers in the front and no spacers in the back since et45 might be just high enough offset to fit in the rear while et40 is a tighter fit (at least judging from posts of people that use the 17x8.5 et40 apex wheels with 245 width tires).

[Gangplank]

Makes sense but it seems 18x8 or 8.5 et40 (or 42) & 18x9 or 9.5 et 58 would work really well for staggered set up.

[swagon]

BBS does. CH-R 18/19x8 ET40 & 18/19x9 ET44. 18's fit just fine with 225/245 tires.

[Gangplank]

Originally Posted by swagon

BBS does. CH-R 18/19x8 ET40 & 18/19x9 ET44. 18's fit just fine with 225/245 tires.

Starting to make sense.


The more I'm searching & researching it seems 18x8 et 45 might work better than 8.5 for running a 245 square set up.

And 18x8 & 18x9 or 9.5 better for 245/255 or 245/265 staggered.

Hmmm....

(Not sure why there is a fascination with wider rims unless its form & fashion over function)

[bNks334]

No... You'll rub in the rear with that low offset and 8.5" rims (unless you stretch your tires or something stupid like that)...

Et45 is used with 8.5 rims so that you can rotate tires front to back. 235 fits perfect with zero rub. Moving to et 40 up front (5mm spacer) with 245s will cause rub for a majority of people. You'd need camber plates to clear the fender.

If the offset is too high in the front than simply space them out a bit to run wider tires and risk rubbing the fender. You can't increase the offset of a wheel... et40 in the rear will require a fender roll. Et45 just barley tucks without hitting the fender...

You also wouldn't want to stuff a 245 tire on an 8" rim either...

et 60+ is better for the rear, but staggered wheels are poor for a neutral handling car. You also don't get as much life out of the tires since you can't rotate front to back.

[Gangplank]

Originally Posted by bNks334

No... You'll rub in the rear with that low offset...

Et45 is used with 8.5 rims so that you can rotate tires front to back. 235 fits perfect with zero rub.

If the offset is too high in the front than simply space them out a bit to run wider tires. You can't increase the offset of a wheel... et40 in the rear will require a fender roll. Et45 just barley tucks without hitting the fender...

et 60+ is better for the rear, but staggered wheels are poor for a neutral handling car. You also don't get as much life out of the tires since you can't rotate front to back.

Makes sense. Seems a good set up might be front 18x8 et40-45 & rears 18x9 et45 (max) to et50-58 - fit a staggered 245/35 & 255/35. Goal being to reduce understeer, add neutral feel & no fender rolling needed. Front would require removing camber alignment pin + camber plates. M3 arms optional.

[drunkenup]

Tire works better on the proper wheel width. Contact patch is on a given tire is wider on the properly wide wheel, at the right width the sidewall has enough flex for longitudinal grip and pinched enough for best turning response and road feel. It's why the F8x ships with 255's on a 9" and 275s on a 10'' wheel.

The best (imo) front end setup would be 255 on a 9'' ET33-ish. Obviously this requires adjustable camber plates and probably some fender work so nobody makes that specific offset. My current 245/35 on 8.5" et45 feels *alright* though I'll probably buy 4x 17x9 et40 arc8s to do 255 square.

Basically the most I'd put on a 18x8 is a 235 or try your luck with a 8.5 square setup for 245s (would easily work with dinan plates alone at ~-2 deg).

[Gangplank]

Originally Posted by drunkenup

Tire works better on the proper wheel width. Contact patch is on a given tire is wider on the properly wide wheel, at the right width the sidewall has enough flex for longitudinal grip and pinched enough for best turning response and road feel. It's why the F8x ships with 255's on a 9" and 275s on a 10'' wheel.

The best (imo) front end setup would be 255 on a 9'' ET33-ish. Obviously this requires adjustable camber plates and probably some fender work so nobody makes that specific offset. My current 245/35 on 8.5" et45 feels *alright* though I'll probably buy 4x 17x9 et40 arc8s to do 255 square.

Basically the most I'd put on a 18x8 is a 235 or try your luck with a 8.5 square setup for 245s (would easily work with dinan plates alone at ~-2 deg).

Agreed 255/35 on 18x9 is a good Fitment. It'll work good on the rear.

On front 245/35 on 18x8 is not out of spec for the top rated 'max performance summer' tires MPSS & PS-04s, also works with Hankook Ventus V12 Evo2 or Hoosier R7.

[Gangplank]

Other two..,

[bNks334]

Originally Posted by Gangplank

Makes sense. Seems a good set up might be front 18x8 et40-45 & rears 18x9 et45 (max) to et50-58 - fit a staggered 245/35 & 255/35. Goal being to reduce understeer, add neutral feel & no fender rolling needed. Front would require removing camber alignment pin + camber plates. M3 arms optional.

18x8.5 ET 40 will work fine up front with 245's. why limit yourself to an 8" rim? 245 is a bit wide for 8". You're concern will be the fender. You might be able to get enough negative camber up front with the alignment pins removed.

M3 control arms don't help since they add negative camber by pushing the bottom of the wheel out instead of tucking the top of the wheel in...

In the rear, 18x9 with anything from ET70 to ET50 should work fine with 255's. I have 17x9 ET45 on the rear of my car, and I needed to roll the inside lip of the fender a bit to prevent rub. ET50 would prevent this.

[bNks334]

Originally Posted by drunkenup

The best (imo) front end setup would be 255 on a 9'' ET33-ish. Obviously this requires adjustable camber plates and probably some fender work so nobody makes that specific offset.

Up front, I was able to get away with as high as ET38 with my 17x9's with 255 RS3's (ET45 with 7mm spacer). This was with stock struts. The tire was maybe 1mm off the strut. ET35 would be perfect.

I warn now that aftermarket suspensions all have too long of a spring which takes away 13mm or more of clearance...

Originally Posted by drunkenup

My current 245/35 on 8.5" et45 feels *alright* though I'll probably buy 4x 17x9 et40 arc8s to do 255 square.

17x9 ET40 will not fir in the rear. You will need to pull your fender. 17x9 ET 45 with 255's rubbed for me. I needed to roll the inside lip of the fender to make them work (no pull). 17x9 ET50 would work better front and rear for an awesome square setup (get some nice 200tw re-71 's). Just use a 15mm spacer up front (to make them an effective ET35)! No modification will be needed at all in the rear, and you'll be able to rotate.

Some people have made 17x9 with 255's work up front with just camber. I am guessing you'd need something like -2.5* or more??? You'd probably need to pull/roll your fenders without the extreme camber...

[John_01]

There was this thread about 17" wheels, but AFAIK it never went anywhere.

Personally I used a track tire setup with 245/40/17 Front and 255/40/17 rear, but I don't have them anymore.