DmcSki wrote Hello all,
Any one have any idea on what size spacers and what’s the best brand to run on my E-92 M3. I have M359 wheels size 18”. The car is on H&R lowering comp springs. I was wondering if I could run a 285 or even a 295 on the rear. Maybe a 265 or even a 275 on the front.
Thanks!
I wouldn't recommend running tires that are too wide for the OEM wheels. E9X M3 OEM wheel widths are 8.5 in wide on the front axle, and 9.5 in wide on the rear axle. Using tires that are too wide for the application wheel width is detrimental for handling and tire tread life. For this reason a recommended rim width range (min and max wheel width) is published for any given tire section width and aspect ratio by the T&RA, ETRTO and JATMA manufacturers associations. Minimum recommended width wheels can certainly be used, but handling will still be compromised (think steering delay, non linear steering, yaw overshoot, poor yaw damping, lack of lateral firmness etc.) when compared to the same tire section width and aspect ratio being used on the
widest wheel width
recommended for it. Particular attention should also be paid to maintaining the tire's outer diameter very close to the OEM tire size diameters to minimize inner fender liner rubbing as well as maintaining gearing. Care should also be taken to keep the ~0.5in outer diameter stagger between front and rear sizes to maintain the suspension roll center locations and roll axis height, as well as speedometer calibration.
Front Axle OEM Wheel Width = 8.5 in wide
Recommended rim width ranges for tire sizes assuming OEM wheels are listed below:
245/40ZR18 rim width range =
8.0 - 9.5 in
255/40ZR18 rim width range = 9.0 - 10.0 in (~0.5in taller tire and 10mm wider than OEM)
255/35ZR18 rim width range =
8.5 - 10.0 in (~0.5in shorter tire and 10mm wider than OEM)
Rear Axle OEM Wheel Width = 9.5 in wide
265/40ZR18 rim width range = 9.0 - 10.5 in
275/40ZR18 rim width range = 9.0 - 11 in (~0.5in taller tire and 10mm wider than OEM)
275/35ZR18 rim width range = 9.0 - 11 in (~0.7in shorter tire and 10mm wider than OEM)
285/35ZR18 rim width range = 9.5 - 11 in (~0.4in shorter tire and 20mm wider than OEM)
OEM Tire Diameters
245/40ZR18 O.D. = 25.7 in
265/40ZR19 O.D. = 26.3 in
IF you really want to run a 265mm or 275mm section width up front then a wheel
wider than 8.5in is recommended (needed) i.e. at least 9.0 inches or wider is preferred.
IF you really want to run a 285mm section in the rear, you can do that on a 9.5 in wide wheel but I don't recommend it, because handling will degrade as well as wear life (irregular wear).
Seems
you can probably get away with running a 255/35ZR18 on the front OEM wheel and a 275/35ZR18 on the rear OEM wheel. These will lower the car another ~0.5in over the stock OEM tire fitment as well as preserve O.D. stagger but the speedo, and gearing will be altered. At stock ride height another alternative would be 255/40ZR18 fronts and 275/40ZR18 rears on the OEM wheels, though this fitment lifts the car ~0.5in over the stock OEM fitment.
Related and reading:
https://www.tirerack.com/tires/tiretech/techpage.jsp?techid=233
Regarding spacers:
https://www.m3post.com/forums/showthread.php?t=336209
15mm front and 12mm rear hub centric spacers have been used my many forum members. Be absolutely sure that the spacers you purchase are hub centered and not stud centered or ride will be compromised due to vibrations. APEX makes some good ones as does Turner Motorsports.
