Loni313

Hello,

I'm Pretty new to the forum, i've mostly just lurked for the past 2 years. I've always found the info i needed by STFA's


I recently purchased a set of 124's for my 530I.. Got a Great deal from a local 545I owner, $675 for the set w/ Tires
Rims came mounted with a practiclly Brand new set of Blizzak LM-25's(no more then 500 miles on them)
Fronts tires are 245/40/18
Rear tires are 265/35/18

My question is, Does anyone see a problem if i mounted a pair of Dunlop WinterSport M3's on the rear? I have two lightly used ones in my garage that are 245/45/18
The reason I'd like to swap them out is i dont like the low profile the rear tires are. They leave a little bit of a wheel well gap that im thinking the Dunlops 45 profile will help close up a little, Plus the Blizzak's low profile is pretty damn low for horrible Michigan roads. Im a little worried about things like, Would i be stretching the 245 a little to fit the 9" rear rims? would the 2 different brand tires or the higher profile on the rear effect the ride?



Any help would be greatly appreciated,

Thanks all

sdg1871

Several issues.

1. It is not generally recommended to mix and match dedicated snows due to the differences in grip of different tires. You are supposed to use them in matching sets of 4.

2. The 245 width tire should fit on the rear 124 wheels. I know that some NYC area members use 245s all around as winter tires on staggered 124 wheels.

3. The 45 series height sidewall is one size more than the recommended height of the tires. The recommended size is 245/40/18. It is possible that you could have rubbing if you have a full load as well as some speedometer error due to a wheel/tire diameter slightly greater than the standard size. One size up is not a major deviation but there might be a little rubbing when under full load if you hit a big bump.

luigi524td

You can compare your tire sizes here:

http://www.miata.net/garage/tirecalc.html

The sidewall height difference of the tires you're mentioning is about .2" ... probably insignificant in the grand scale of things. I agree, that mixing tire brands is now recommended and that extreme low profile tires and bad roads are a recipe for expensive issues.

Loni313

Thanks a lot, I'll just leave them alone for now

When i purchase summer tires in the spring will it be ok to have 40's all around?

Loni313

Thanks for the link,
Roads out here suck, i had allready bent a stock 17" wheel with stock profile tires
Going to have to keep my eyes out for pot holes =/

GregBrand

I am running 245 x 45 front and 275 x 40 rears (18" BMW 124s) on my '08 535xi and no rubbing fully loaded.

These tires nicely fill the wheel well gap so no need to alter the world-class BMW engineered suspension.

My tires are Michelin Pilot Sport PLUS A/S. I also have 15mm spacers on the rears. Good luck.

luigi524td

Meant to type NOT recommended to mix tire brands / styles.