[MerlinMc]

For 18X8 and 17X8 wheels running 245 width tires in a square set up, what would be the perfect offset? Key considerations include:

• No rubbing or other interference.
  
  
• No modifications necessary such as fender rolling, camber adjustments, spacers, etc.
  
  
• Good "visuals" such as not too inset or sticking outside the fenders.

Thanks!

[jondagger]

Originally Posted by MerlinMc

For 18X8 and 17X8 wheels running 245 width tires in a square set up, what would be the perfect offset? Key considerations include:

• No rubbing or other interference.
  
  
• No modifications necessary such as fender rolling, camber adjustments, spacers, etc.
  
  
• Good "visuals" such as not too inset or sticking outside the fenders.

Thanks!

I would say fronts should be et35-et37 with some -2 to -3 front camber.... additional mods needed... to avoid the $600+ for camber, maybe roll and pull fenders.

Rears i would do et37... I run that with my OEM wheels w/ 15mm spacers.. OEM is et52 with 15mm spacer it is essentially the 18x8et37 with 245/35zr18 Michelin PS4S..... i love the look

This should leave you flush up and down....

furthermore:
I currently run et33 in the fronts with the OEM wheels and 12mm spacers, could do 15mm spacers and more... so 18x7.5et33 w/ 225/40zr18 on MPS4S is my setup.... i could not tell you exactly how to get to 245 from my current setup (+10mm each side).... but due to the fact i have lots of room between wheel and fender now, the et35-et36 seems to be the right fit for the job... Someone on a recent post did et35 on -3 camber... he was lowed 1 inch in the front too... claims 2mm of room left to fender.....

[PeterWT]

Originally Posted by MerlinMc

For 18X8 and 17X8 wheels running 245 width tires in a square set up, what would be the perfect offset? Key considerations include:

• No rubbing or other interference.
  
  
• No modifications necessary such as fender rolling, camber adjustments, spacers, etc.
  
  
• Good "visuals" such as not too inset or sticking outside the fenders.

Thanks!

https://www.2addicts.com/forums/show....php?t=1597122

[MerlinMc]

Originally Posted by PeterWT

https://www.2addicts.com/forums/show....php?t=1597122

Thanks, Peter. I have read this thread extensively. It seems like et 43 works with 245 width tires. Could maybe go to 40 or high 30s in offset?

[MerlinMc]

Thanks again to XutvJet (OP) for his post on another thread. Thanks to all of those on this thread for their thoughts. All helpful and much appreciated.

Test fit my OZ Leggera 18x8 et 45 wheels with 245 width Michelin PS4 tires all around.

In the front, there is very little room between the strut and tire. I tried adding 5mm spacers, but this moved the tires out to almost even with the outer fenders. Some might like that look, but I like the tire to be inset a little at the top. Et 43 is appears to be the perfect offset for 245 width PS4s. I encountered no rubbing with the et 45 and no spacers. Did full lock circles in both directions. There would be an extra safety margin at et 43.

In the rear, the et 45 works great with loads of room. It sits further to the outside than the stock et 52 wheels. The rear would probably work well with the 5mm spacers to get to et 40.

[Maynard]

Thanks for the info and comparison. Do you know the stock offset for the front 7.5" wheels? I'm wanting to calculate clearances for an 8.5" wheel w/ 235's.

[MerlinMc]

Originally Posted by Maynard

Thanks for the info and comparison. Do you know the stock offset for the front 7.5" wheels? I'm wanting to calculate clearances for an 8.5" wheel w/ 235's.

The current (2020) M240i front offsets are 45, I think. I think the rears are 52. Not sure about other years.

[dradernh]

Originally Posted by Maynard

Do you know the stock offset for the front 7.5" wheels?

ET 45 on my 2017 M240i.

[hwntime]

Originally Posted by MerlinMc

The current (2020) M240i front offsets are 45, I think. I think the rears are 52. Not sure about other years.

7.5Jx18 ET45
8Jx18 ET52

[jondagger]

Attached are photos of below specs.
Rear: 18x8 et37 (245/35/18 PS4S)
Front: 18x7.5 et33 (225/40/18 PS4S)

Rears have around 5mm of room to fender...
Fronts have 8mm or more room to fender...


I would say the safe bet is 18x8 et40 for fronts with 245/40/18..

Anything with more inside than 18x8et42 will run on struts. anything more aggressive than et35 will need camber.

[MerlinMc]

Originally Posted by jdag001

Attached are photos of below specs.
Rear: 18x8 et37 (245/35/18 PS4S)
Front: 18x7.5 et33 (225/40/18 PS4S)

Rears have around 5mm of room to fender...
Fronts have 8mm or more room to fender...


I would say the safe bet is 18x8 et40 for fronts with 245/40/18..

Anything with more inside than 18x8et42 will run on struts. anything more aggressive than et35 will need camber.

I have 18x8 et 45 wheels with 245 width Michelin PS4 tires all around (see above). It's very tight to the struts in the front but no detectable rubbing. I may put 3mm spacers on the front to move the wheels out.

[jondagger]

Originally Posted by MerlinMc

I have 18x8 et 45 wheels with 245 width Michelin PS4 tires all around (see above). It's very tight to the struts in the front but no detectable rubbing. I may put 3mm spacers on the front to move the wheels out.

Are you lowered? doesnt seem like you are....What is your camber if your lowered?

If you were to get a drop? would you rub? any poke? could you get some poke photos? eg. top or front views

[MerlinMc]

Originally Posted by jdag001

Are you lowered? doesnt seem like you are....What is your camber if your lowered?

If you were to get a drop? would you rub? any poke? could you get some poke photos? eg. top or front views

You're correct: it's not lowered -- all stock.

Will take some photos from the top down this weekend. The top of the tires are still inside the fender (no poke).

[MerlinMc]

Originally Posted by MerlinMc

You're correct: it's not lowered -- all stock.

Will take some photos from the top down this weekend. The top of the tires are still inside the fender (no poke).

Here are some images of the front wheels & tires. The wheels are 18X8 et 45 with 245 width tires. No spacers and there is no poke. The first image is straight down. The second is at an angle. If anything, the wheels may still be too inset.

[jondagger]

Originally Posted by MerlinMc

Here are some images of the front wheels & tires. The wheels are 18X8 et 45 with 245 width tires. No spacers and there is no poke. The first image is straight down. The second is at an angle. If anything, the wheels may still be too inset.

Beauties! and thanks for the followup. I will probably go et42 with 245s up front. Rears its maybe et52 with 265s

[Maynard]

Thanks to all for the size info and pics. I'm deciding to stick with a more conservative +0.5 bump in rim width and stock tire sizes, as I don't want any significant poke.

FWIW, 245 is the widest tire for an 8" rim (in the guides I've seen) - I think you need a 9" wheel to safely fit a 265. You can physically run wider tires on an 8, but I wouldn't want to drive it that way.

[MerlinMc]

I added some 3mm spacers to the front wheels; so the 18x8 45mm offset wheels become 42mm. Still no poke with the 245 width tires.

These photos are with the spacers installed. Car still drives nicely and has a couple more mm of clearance inside.

[jondagger]

Originally Posted by MerlinMc

I added some 3mm spacers to the front wheels; so the 18x8 45mm offset wheels become 42mm. Still no poke with the 245 width tires.

These photos are with the spacers installed. Car still drives nicely and has a couple more mm of clearance inside.

IMO i dont think you could afford a suspension drop under under these exact constraints. Camber will probably be needed for full clearance. Correct me if you think otherwise.

Regardless, to use that 245tire to its fullest, i highly suggest some aggressive negative camber up front.

[MerlinMc]

Originally Posted by jdag001

IMO i dont think you could afford a suspension drop under under these exact constraints. Camber will probably be needed for full clearance. Correct me if you think otherwise.

Regardless, to use that 245tire to its fullest, i highly suggest some aggressive negative camber up front.

There is probably room to lower the suspension though I don't plan on doing lowering as this is my daily driver.

Some negative camber would likely improve the handling with the 245s though the car is already more nimble just by swapping the 245s for the 225s.