If I'm not mistaken, Esso/Texaco/BP/Jet's finest are 97 RON, Shell Vpower and Tesco Momentum are both 99RON. Once upon a time BP had 102RON fuel, but they stopped it. It's not uncommon to see supercars, and GTIs, Audi S/RS and BMW M spec cars (not Msport trim) filling at my local tesco, guess they are putting Momentum 99. My personal experience on a non-performance car, Shell Vpower gave me best Mpg, Esso Supreme 97 gave me the smoothest engine having tried all the non-supermarket petrol. Cannot feel any difference in power in any.