Hey so I noticed that the dealer had all 4 tires the same size for my 2010 panamera s (255/40zr20 pirelli p zeros)....the rears should be 295 but it's a square setup with all tires the 255/40zr20 size)

is this a major issue having this kind of tire setup? I notice the TPMS displaying PSI numbers that arent accurate to what the tire shop says when they checked my tire pressure, is this due to the square tire setup?

Any issues that may arise on this kind of tire setup? Thanks all.

 

If you bought it from a Porsche dealership, bring it back to the dealer and tell them to get the Porsche OEM size rear tires for your vehicle 295/35R20.

 

Are there any issues (besides it doesnt look as good) if all tires are same size on the panamera s?

 

I'm not a suspension expert so I can't answer your question with authority. I do think that you will not get the best handling, ride and safety with your current setup. Porsche spent thousands of hours of development to come up with their recommended tire sizes. The different front and rear tire sizes are what Porsche thinks are optimum for their vehicles. Not sure why a legitimate Porsche dealer would sell you a Porsche that doesn't match factory standards.

 

I posted a thread with Panamera tire info. Click Here to avoid searching yourself. Hope it helps.

 

The wheels should be different sizes, too. Incorrect tire circumference/diameter (expected difference between front and rear) will affect the PSM system.

 

I presumed it would mess up the psm, could this be the reason I am experiencing throttle lag or jerkiness??

 

Unrelated. Excessive difference in tire size (delta front to back) would may cause a PSM warning/error. Do you get throttle lag or jerkiness in Sport mode?