Originally Posted by g35brother

Ok so I'm exhausted from searching, whats the word with oem rims and running different tires? Why is it not recommended yet its OK if people buy wider rims and its ok then to run wider tires and not affect the VDC/ABS. A discount rep just advised me against running 245/35/19f and 255/40/19 rear because his manual says it will lead to ABS and VDC failure with stock rims? Why does this not happen if I bought 19x8 and 19x9.5 rims with respective tire sizes like 245/35/19 and 275/35/19

Originally Posted by romanwarrior

the key to replacing tires with different sizes is to get close as possible to the OE tire overall diameter. you said that you are going to use your OE wheels (fr, 19x8.0 & rr, 19x8.5) and just get different tires. it seems like you want to get wider tires... since you're using your stock wheels, you can't get the same tire overall diameter as your stock tires.

Stock Tires:
225/40R19 = OD is 26.1 inches
245/40R19 = OD is 26.7 inches

+0 Up-Sizing:
245/35R19 = OD is 25.8 inches
265/35R19 = OD is 26.3 inches

Both tire sizes that I recommended are the widest you can go on 19x8.0 and 19x8.5. If you go with a lower aspect ratio on your rear tires, you speedometer reading will be way off as you increase volocity. If you want to have the same OD as your OE tire sizes, then you would have to buy wider wheels... at least 9.5-inches wide for the rear wheels to accomodate a 275/35R19 (OD is 26.6 to 26.7 inches depending on the tire manufacturer).

Hope this helps.