In regards to the Michelin tires be advised that they have changed lately. they still keep the XGT *4 moniker but the new style carries the Pilot name beforehand. Ghislain mine are the Pilot XGT H4 and you have had a chance to feel how they hook up. I also had the plain XGT H4 on the car and the diffeence is night and day. The tires on the SiR use a different tread pattern similar to the older XGT's and I have also found that the Pilot series makes two different tread patterns in the v-rated tire, one using the old style XGT tread pattern similar to the BF Goodrich (kinda looks like fat v's turned sideways and the new style whick are an all weather directional style tread.