Tire size

Hey guys good to be back
I recently re-purchased my 2011 e93 and I’m looking to purchase a set of summer tires. There is still room in the front to fill the wheel well (see attached pics) and I wouldn’t mind a larger overall wheel / tire look in the process. That front pic is a pirelli but the Michelin had the same gap

Currently running
APEX FL-5 18”
F 18x9.5 +28
R 18x10.5 +22
Michelin pilot sport 4s
F 265/35/ZR18 circumference 25.3”
R 285/35/ZR18 circumference 25.9”
Slightly lowered sitting on Einach springs

Also previous owner dialed in more camber that I plan to dial out. The alignment spec I liked the most for my driving was:

Front:
Camber -1.2° ± 0.3°
Caster 6.5° ± 0.5°
Total Toe 0.07° ± 0.07°

Rear:    
Camber -1.6° ± 0.2°
Total Toe 0.17° ± 0.08°

Kicking around a couple
Ideas - would love your thoughts

1. In the Front run 275/35 vs 265/35
2. Pick a tire that is more sq shouldered (but I love the PS4s)

Neither of those two get me a bigger wheel/ tire combo look … would
Also like thoughts on bumping to 40 from 35 on the sidewall spec

Thanks
-Alan

I have 9.5"/10.5" 265/285 as well. I don't think there's a better choice. You could go with a tire like cup 2 that has a fatter sidewall which will fill out a tiny bit more. More expensive. stickier at 240tw versus 300tw, but not bad. Fewer miles out of them as well.

I’ll check that out as mileage won’t pile up as fast as previous years.

Any thoughts on going to a 40 sidewall vs 35?

That's too tall. Slows the car a little (less leverage), might confuse dsc system. Will look a little funny.

M3BatMobile wrote

I’ll check that out as mileage won’t pile up as fast as previous years.

Any thoughts on going to a 40 sidewall vs 35?

Stock 245/40-18 and 265/40-18 sizes are fine in 40 series but as you increase width, you have to decrease diameter/sidewall height.

The second picture is a winter tire, correct?

I would go with a 275/35 front and 285/35 rear setup over the 265/35 and 285/35 setup. The 275/285 is close to a square setup so it’ll remove a little more understeer from the handling balance which is always an improvement. I wouldn’t look for a more square shoulder tire for street use. A square shoulder makes a tire have an abrupt breakaway characteristic when driven at the limit while a rounded shoulder is more forgiving and starts to squeal louder the closer you get to the limit.

M3SQRD wrote

The second picture is a winter tire, correct?

I would go with a 275/35 front and 285/35 rear setup over the 265/35 and 285/35 setup. The 275/285 is close to a square setup so it’ll remove a little more understeer from the handling balance which is always an improvement. I wouldn’t look for a more square shoulder tire for street use. A square shoulder makes a tire have an abrupt breakaway characteristic when driven at the limit while a rounded shoulder is more forgiving and starts to squeal louder the closer you get to the limit.

I know there are may posts but would the 285R/275F fit with BMW 359’s? I’m adjustable height so I can figure that out but I’d like to be 1” lower than ZCP and not rub.

Scrippy wrote

I know there are may posts but would the 285R/275F fit with BMW 359’s? I’m adjustable height so I can figure that out but I’d like to be 1” lower than ZCP and not rub.

The zcp 359m is 19x9et31 and 19x10et25. The ideal width for a 9” wide wheel is a 265 (fyi, a wheel width is measured from the inner-tire seat to inner-tire seat while the outer-tire seat to outer-tire seat is 1” wider than the spec’d wheel width; e.g., a 9.0” wide wheel has an outer-tire seat to outer-tire seat width of 10”). A narrower wheel cannot provide adequate support for a tire so a 275 is too wide for a 9” wheel. Yes, a 275 would fit on a 9” wheel but you wouldn’t be able to extract the full potential straight-line and handling grip from the 275. This will also affect the tire breakaway characteristic, which becomes more of an abrupt loss of grip, instead of a progressive loss in grip with increasing slip angle. A 275 ideal width is 9.5”. If you’re more concerned about aesthetics than performance and drive at 8/10ths or less then you could mount a 275 on a 9” wheel. Similarly, a zcp 10” wide wheel ideal tire is a 285 but a 295 would fit with the same issues as a 275 on a 9” wheel.

Now to answer your question, a 275/285 staggered tire setup could be used on zcp 359m wheels with the noted changes in the 275 tire characteristics. I know a 265 will work on the front with adequate clearance between the tire and front strut; however, I do not know if a 275 on a 19x9et31 wheel will have adequate clearance with the front strut but you’d probably only need a 3 or 5 mm spacer to have sufficient clearance with the front strut. To balance things out, you could use the same 3 or 5 mm spacer on the 19x10et25 rear wheel with zero rubbing concerns. I run my 275/35-18 on an 18x9.5et22 wheel which has a large amount of clearance with the strut.

M3SQRD wrote

The zcp 359m is 19x9et31 and 19x10et25. The ideal width for a 9” wide wheel is a 265 (fyi, a wheel width is measured from the inner-tire seat to inner-tire seat while the outer-tire seat to outer-tire seat is 1” wider than the spec’d wheel width; e.g., a 9.0” wide wheel has an outer-tire seat to outer-tire seat width of 10”). A narrower wheel cannot provide adequate support for a tire so a 275 is too wide for a 9” wheel. Yes, a 275 would fit on a 9” wheel but you wouldn’t be able to extract the full potential straight-line and handling grip from the 275. This will also affect the tire breakaway characteristic, which becomes more of an abrupt loss of grip, instead of a progressive loss in grip with increasing slip angle. A 275 ideal width is 9.5”. If you’re more concerned about aesthetics than performance and drive at 8/10ths or less then you could mount a 275 on a 9” wheel. Similarly, a zcp 10” wide wheel ideal tire is a 285 but a 295 would fit with the same issues as a 275 on a 9” wheel.

Now to answer your question, a 275/285 staggered tire setup could be used on zcp 359m wheels with the noted changes in the 275 tire characteristics. I know a 265 will work on the front with adequate clearance between the tire and front strut; however, I do not know if a 275 on a 19x9et31 wheel will have adequate clearance with the front strut but you’d probably only need a 3 or 5 mm spacer to have sufficient clearance with the front strut. To balance things out, you could use the same 3 or 5 mm spacer on the 19x10et25 rear wheel with zero rubbing concerns. I run my [...]

Thanks for the reply. I appreciate the info. I will re-read tomorrow when the garage sodas wear off. lol I feel like I absorbed 23% of that.

M3SQRD wrote

The zcp 359m is 19x9et31 and 19x10et25. The ideal width for a 9” wide wheel is a 265 (fyi, a wheel width is measured from the inner-tire seat to inner-tire seat while the outer-tire seat to outer-tire seat is 1” wider than the spec’d wheel width; e.g., a 9.0” wide wheel has an outer-tire seat to outer-tire seat width of 10”). A narrower wheel cannot provide adequate support for a tire so a 275 is too wide for a 9” wheel. Yes, a 275 would fit on a 9” wheel but you wouldn’t be able to extract the full potential straight-line and handling grip from the 275. This will also affect the tire breakaway characteristic, which becomes more of an abrupt loss of grip, instead of a progressive loss in grip with increasing slip angle. A 275 ideal width is 9.5”. If you’re more concerned about aesthetics than performance and drive at 8/10ths or less then you could mount a 275 on a 9” wheel. Similarly, a zcp 10” wide wheel ideal tire is a 285 but a 295 would fit with the same issues as a 275 on a 9” wheel.

Now to answer your question, a 275/285 staggered tire setup could be used on zcp 359m wheels with the noted changes in the 275 tire characteristics. I know a 265 will work on the front with adequate clearance between the tire and front strut; however, I do not know if a 275 on a 19x9et31 wheel will have adequate clearance with the front strut but you’d probably only need a 3 or 5 mm spacer to have sufficient clearance with the front strut. To balance things out, you could use the same 3 or 5 mm spacer on the 19x10et25 rear wheel with zero rubbing concerns. I run my [...]

I have always done 265 rear and 245 front but I think I’m gonna try 285/265. Think I can still run my 12 & 15mm spacers or maybe reduce those down?

Scrippy wrote

I have always done 265 rear and 245 front but I think I’m gonna try 285/265. Think I can still run my 12 & 15mm spacers or maybe reduce those down?

Are these stock 18” 219M (18x8.5et29 & 18x9.5et23) or 19” 220M (19x8.5et29 & 19x9.5et23) or 19” 359M (19x9et31 & 19x10et25) wheels?

The F/R 265/285 tires should be used with 359M F/R 9/10” inch wheels. 219M and 220M F/R 8.5/9.5” wheels should keep tires limited to F/R 255/275 tires.

A 15 mm spacer on a rear 359M 19” rear wheel with a 285 might be a little too aggressive but a 12 mm spacer with a rear 359M and a 285 tire should work. I’m running a 285/35-18 rear tire on an 18x10et17 and it works great so a 285 on a 19x10et13 (et25 with a 12 mm spacer) is only 4 mm more aggressive. Worst case, you might need to run -2.0 to -2.1 deg of rear camber (I’m running -1.85 deg of rear camber). For the front, I run an 18x9.5et22 with a 275/35 tire which is very close (0.013” less aggressive) to a front 19x9et16 with a 265/30 tire so the front 359M wheel with a 15 mm spacer and a 265/30 tire should work. To summarize:

-359M front 19x9et15 effective offset with a 15 mm spacer + 265/30 tire should work fine.

-359M rear 19x10et13 effective offset with a 12 mm spacer + 285/30 tire should work. Worst case, you might need to increase camber to -2.0 to -2.1 deg.

-219M or 220M F/R 8.5/9.5” wide wheels should work fine with F/R 15/12 mm thick spacers and F/R 255/275 tires.

Sorry for the delay. I worked in a response that glitched and didn’t get posted

To answer youre question you are Correct, winter tire on the front pic. She came back with her shoes miss matched 😂

this discussion has been very helpful and made me realize I asked the wrong question as I am trying to get a look/ stance with the existing eibach springs, oem struts and apex 18” wheels.

I now realize I likely need to change the ride height and bump to 19” wheels

You sound like you might be able to figure out the wheel offsets that replicate the set up tom put together using these spacers on a set of BBS Rev7 wheels
——
Macht Schnell Competition Spacer Kit, 05mm (10mm total track)
Macht Schnell Competition Spacer Kit, 12mm (24mm total track)
——
I want to replicate this
Look and stance in this post without spacers. Hopefully it wouldn’t take a custom wheel to accomplish this

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