Help! Which tyres for 8.5 front wheel?

[inkey$]

Yes, the age old question. Situation as follows and I need some help/opinion....

Current Setup
Running MV2 staggered wheels on very new Goodyear Eagle F1's
Front: 18 x 8J ET47 with 225/40/18
Rear: 18 x 8.5J ET50 with 255/35/18

New Setup
Bola B1 square 8.5
Front: 18 x 8.5J ET40
Rear: 18 x 8.5J ET33

My first thought was to just swap the tyres from the MV2's to the B1's, however the 225 width of the Goodyears I have on the MV2's are the minimum you'd want to go on an 8.5 wide rim.

Do you think this would stretch too much and look odd? I basically want the wheels to look 'normal' with the tyres and offer at least some rim protection, so if its too much of a stretch I may need to get new Goodyears for the front - but if so, what width would work and look best?

235/40/18? Slight change in rolling speed, but would they offer more rim protection and not look too stretched?

[mmm-five]

Time to put a set of SuperSport R on I think, and keep the other wheels/tyres for the winter

[brillomaster]

Square wheels = square tyres?

[inkey$]

Square wheels = square tyres?

Square setup = same width on each corner

[brillomaster]

Yes i mean, so why not 255s on all corners too?

I have previously paired a 245 35 18 front with a 255 35 18 rear, to maintain a bit of stagger and add a bit of rake, worked well for me?

[inkey$]

Yes i mean, so why not 255s on all corners too?

I have previously paired a 245 35 18 front with a 255 35 18 rear, to maintain a bit of stagger and add a bit of rake, worked well for me?

Ah, okay! Got it. I’ve looked at the following on an 8.5 front on the very handy willtheyfit.com:

• 245/35/18 = plus 1.35% speedo error / -4.25mm arch gap loss

• 245/40/18 = minus 2.45% speedo error / 8mm arch gap gain

• 255/35/18 = plus 0.24% speedo error / -0.75mm arch gap loss

• 255/40/18 = minus 3.63% speedo error / 12mm arch gap gain

…so from that it looks like for decent rim protection, the 255/35/18’s look best, right? Which would make sense since thats what it would be on the rears.

* I’m aware I just answered my own question

[inkey$]

Just ordered a pair of 255/35/18’s for the fronts, so will be running square wheels and tyres front and rear with the new setup

[Pbondar]

Just ordered a pair of 255/35/18’s for the fronts, so will be running square wheels and tyres front and rear with the new setup

That's a lot of tyre for the front of an E85?

[inkey$]

Just ordered a pair of 255/35/18’s for the fronts, so will be running square wheels and tyres front and rear with the new setup

That's a lot of tyre for the front of an E85?

Clearances work out and its minimal speed and arch gap change, so should be fine.
(And its an E86)

[inkey$]

These are the diagrams Im getting back on the three tyre width fitments - 255, 245 and 235 - all at 35 and R18.
Differences to speedo and arch gap as per my list above.
The 235/35/18 are coming in at +2.49% speedo error and -7.75mm arch gap loss.

Oragne line = MV2 wheel size with 225’s - Green line = new tyre sizes

D0495643-895F-419B-841C-BE610AC62B09.jpeg (52.02 KiB) Viewed 957 times

[brillomaster]

When they are on you might wanna mark the fronts and the rears in some way, would be easy to mix them up on a dark night when the only difference will be 7mm of offset!

[inkey$]

When they are on you might wanna mark the fronts and the rears in some way, would be easy to mix them up on a dark night when the only difference will be 7mm of offset!

Im a proper novice with tyre and wheel sizes. Its one of those subjects that I want to understand but my mind wont accept it

Offsets of the actual wheels are ET40 front and ET33 rear, so should fill the arches nicely and spacer-free, with an extra poke of 13.4mm at the front and 15mm on the rear.

I just cant get my head around the tyres. I’m running standard suspension, I don’t want rubbing issues and I really don’t want the stretched tyre look as I think it looks horrendous.

255/35/18 would be square on all corners - and with the ability to swap fronts for rears if need be - but would they add too much extra poke to the 13mm offsets on the front and stick out like a sore thumb/sticky out wheels?

Still massively confused!

[Haggisman]

I put 235 x 40 x 18 on my E85 with 8.5 x 18 et 38 and had rubbing with the Michelin ps4’s. Had to change to 225 x 40 x 18. Your et 40 will help as the rubbing I had was on the liner on the front outer edge, the photo may help.

[Haggisman]

Photo re above post

[inkey$]

Thanks Haggisman. So you think the 235/35/18 tyres with my offset would clear the inner lining okay but not look stretched?

I also just did a comparison on wheel-size.com of the 245 and 255 width tyres.

72A38405-6C0B-4092-BE26-762DE018843A.jpeg (71.72 KiB) Viewed 918 times

Maybe I just try and swap all tyres to the new setup and see if the front 225 tyres look wrong or not. They’ll provide the most clearance and least change.

With the 13mm offset poke I get from the new ET40 wheel it will be interesting to see how it works out. If it looks bad or handles terribly then I may need more help!