Peterborough Tescos have the 99RON fuel in. I tell ya, if Ben Johnson p!ssed in the tank the car could not go any faster!
I usually use 95RON and now and again get a couple of tanks of super. So I thought I'd try the tesco 99RON (this week @ 93.9p/l) and waited a 100 miles or so. Now going full throttle in 2nd/3rd will try to light the tyres up where it wouldn't before (yes, it was dry tarmac!), even on 98RON Optimax. I do notice more exhaust noise too like a couple of others do, sounding a heck of a lot more agressive, not necessarily louder. For that reason, I think I'll revert back to 95RON as I believe something's going to let go with the extra torque! Better be safe than sorry.
Gets the thumbs up by me, but remember extra power means extra where and tear. I'm into longevity.