fuels and performance

[Dave_Obsession]

Just an observation I've picked up on whilst driving around.....

Whilst my engine is stock (ie runs on regular 91RON unleaded), I have usually been running on BP Ultimate......I guess the videos on their site about the cleaning stuff in the petrol got to me....I want to keep my engine clean inside!!

Anyways, on the 98RON stuff, when accelerating, I can really feel the difference at 2500rpm when the engine just seems to pick up a lot in the higher rev band, right through to 4000rpm (is this when the stock cam seems to die out?).

Just filled it right up last night with the 91RON regular stuff, and the kick at 2500rpm is no longer there, it's more like a constant acceleration with no real noticable improvement at any level......

Does this mean that the car runs better and faster on the 98RON, even if everything is stock??

I don't know all the technical stuff to do with cams, timing and all that stuff......How would some of you more learned guys explain this in laymans terms???