There would be a definite difference, my Z4 used to run miles better on 98/99, the SLK doesn't seem to prefer either TBH. I'd imagine on 102 it would a similar difference.
Alot of people say that there is no difference between standard unleaded and the Ultimate stuff. I have to say I had to put normal 95 in my M once because couldnt get to a garage with Ultimate before running empty. The difference is quite pronounced IMO. 95 seems to sap all of the torque and it just feels nowhere near as urgent.
Cant say I have noticed this BP 102, the highest I have found is the premium stuff at Tesco but I would be interested in what people say about the 102 if theyve tested it!
