and it might be in my head but I swear it's not as quick if I run regular.
For what my two cents is worth: the original S80 2.0T I drove the lady owner didn't know what grade of petrol she used-just the cheapest. Worse still, I could not tell if it was turbo-charged either. The car's performance was bad. She never used the kick-down-she didn't know what it was or what it did!!
When I got my S80 and used the 98.4 octane BP Ultimate petrol-the performance spoke for itself. I knew it was turbo-my car turns into a V8 with very little effort.
Also, I notice that my oil stays a lot cleaner a lot longer now that I am using the 98.4 octane petrol. I definitely don't imagine that.
I think the expense is worth it in the long run. I notice that the car starts easier also.
Cheers