Quote:
Originally Posted by Signature Wheel BMW
Quote:
Originally Posted by euro*
That delta thing just threw me off also. Can people explain please  : |
OEM tire height front is 661mm and 695mm rear (255/35/19 front and 275/35/19 rear). The rear is 2.2% taller than front out of the box.
265/35/19 = 669mm tall
295/35/19 = 689mm tall
305/30/19 = 667mm tall
If you go 265/35 and 295/35, then rear is 3% taller. Within 1%, ECU won't intervene.
If you go 265/35 and 305/30, the front and rear is nearly the same diameter. At 100mph, your rear wheel is spinning 2.2mph faster than the front compared to OEM specs. So your computer thinks your rear wheels are slipping, so it will attempt to reduce power to reduce wheel spin (not ideal for high speed use). This is the "twitching" some described at high speed with incorrect after market setup. So coding Euro MDM and run in MDM would help or turn all nannies off at high speed (I don't recommend unless you know what you're doing).
You "could" do 275/35 front and 295/35 rear, which puts the rear close to stock at 2% larger than the front. However, not all tires are created equal. MPSS 275/35 are wide and "might" rub while Pirelli P-Zero 275/35 front are narrower and won't rub. If you go 275 MPSS, then you must be prepared to make minor camber adjustments to prevent rubbing. |
Wouldn't a 265/35/19 front, 285/35/19 rear combo be closer to stock ratios? (On a 10.5" wheel on the rear)