You ARE responsible ****, you told him exactly what to do lolololol

Kyle his advice is all spot on so do what he suggested and you should be very happy with the results. BTW what wheels are you looking at picking up and what color is your coupe?

Conissah thanks for all the help......

 

Don't wanna just butt into the thread here but is that true about the VDC? I had 255 35 20 front and 285 35 20 rear with no issues (as expected) and then went to a 285 30 20 rear which is actually a tad smaller than the front - but still no VDC issues.

 

These are the wheels im getting and its a black coupe https://lmr.com/item/WK-1007DBK/94-0...lat-black-18x9

 

That's what I was told since I've owned the G and been on these forums. If the rear is outside of 3% rule, the VDC will just always be off. Not a huge deal for me, cause I drive like a grandma, but I could see how it would be annoying. This is a quote from a thread in 2011.

 

obender is close with his advice but he missed saying the important part. TIRE diameter is the important size to consider because it's what creates the revolutions per mile and a hell of a lot easier to use when calculating the difference in tires to see if they fall within the 3% rule. There are a ton of tire calculators on the internet and a good one here at the top of this very page. (If you use it to calculate diameters of tires you can ignore the wheel size/offset categories, they become irrelevant for our purpose)

So using Brad's numbers for example, the 255/35/20 and 285/35/20 have a .83" difference or 2.97%

255/35/20 vs 285/30/20 have a .3" difference or 1.1%, therefore no issues with either set-up. I've skirted the 3% rule by accident once out of necessity for a spare (3.3% difference) and VDC, SLIP and ABS lights all lit up and the car freaked out. It's not a pretty sight when it happens and in the almost 8 years I've been a member here I don't remember anyone posting they exceeded 3% with any success.

 

That's interesting. My first tire setup on these wheels was 245 35 20 front and 285 35 20 rear (I then went 255 up front and only recently went 35 to 30 in the rear)

The calculator I used shows up with that being a 4.1% difference - may be more or less with the one you used - but it's definitely going to be over 3%. Never had any issues.

More interesting info. About a week ago I was running the spare on the rear and when accelerating past 5/10mph the slip light would flash a few times and then all the lights would come on to say ABS/VDC is disabled. This would stay that way until the next ignition cycle. This was also with the larger 285 35 20 tire. Last weekend when I had my puncture the spare was thrown back on again, this time with the 285 30 20 tire. However, there was no "slip detected" at lower speeds but once I got to about 30mph the slip light would flash and I was unable to get to higher speeds. The speed was limited and the light would only go off if I coasted or carried on at lower speeds. The only way to over come this was to turn off VDC.

A bit off topic - being left/right difference in rolling circumference vs front to rear - but worth mentioning.

 

Interesting info, you're the first I can remember that's had success violating the 3% rule. But, I'm old and could have read it before and not remember lol. Thanks for your insight......