Hi All-

I would really appreciate some help.

I have a 2011 cayenne v6 with OEM 18 inch wheels. I was planning on purchasing OEM 2008 21 inch wheels.

Will I run into any problems installing them on my car? Spacers need? Suspension? Etc...

Also how do I reprogram the car's computer for ABS, speedo, etc... for the increased tire size and weight?

If someone could provide some peace of mind I would really appreciate the feedback and help!

Thanks again for all your help!

Jason

 

They should fit fine. If you run oem tire sizes the overall diameter is the same as before because the tire sidewall height gets shorter. With 21" you be running a lot more low profile tires. This will increase the sensation of "riding on rails" with sharper turn in and less sidewall flex... but bumps and road irregularities will be felt much more than before. Some think above 20" starts to feel harsh on steel springs (less so with air suspension)...YMMV. If you have rough roads where you live you may want to factor that in. Also, there will be less tire choices in that size than before and they will be more expensive.

255/55-18
295/35R21 = about 35% less tire height.

 

Great very helpful. Sinze both are OEM, I shouldnt need to fear suspension clearance, correct?

Also Porsche dealer said I needed bring in to reprogram for ABS and speedo. Do I need to bring the car in to reprogram the ABS, or should it work fine?

 

I have no idea why you would have to reprogram the ABS and speedo if the overall rolling diameter is the same. I think perhaps the dealer is trying to program you into paying them money for nothing.

 

awesome, just what I thought.

And how about arch extensions? I thought I read somewhere that 21 inches require arch extensions. Can anyone comment?

Thanks!

 

Someone with a 958 will have to chime in for that.

 

It will definetly look better with the wheel arch extensions for large wheels, Suncoast was selling them for around $370. You can also get them primed and have them painted to the color of the vehicle, which I have been thinking about doing.

 

I don't think you need arch flares if that is what your referring too. The arch flares make the car appear wider. The offset on the OEM 21" are 50mm so they wont stick out far.
p.s. Im the one sellin the wheels on craigslist in san mateo.

 

hahaha. funny. I have both 18s and 21s. just go into the PCM and set the tire/wheels to 21in.

 

Do you guys knowing the tpms from an 08 GTS 957 would work on 11 958?