last weekend, changed my stock michelin RS-As for P7000SS. I upgraded the P7000 size to 225/50/16 vs my stock RS-As at 215/55/16.

I have this impression my speedometer is out of whack since it seems like I'm going pretty fast on the highway...or perhaps its just (hardly any) rolling resistance from the P7000SS?

someone pls help me?

thanks

 

no. everything is good

 

It shouldn't be a huge difference from the 215/55/16's. The 225/50/16 wheels have a total diameter of 631.4 mm while the 215/55/16 whels have a total diameter of 642.9 mm. That amounts to a difference of about .45 inches. Your speedo may be slightly off because of this.