I used to own and I modded a focus St 5 cyl to over 320 bhp and would always use Tesco's or Shell high octane. I cant comment on making it any faster as that wasnt the reason for using super in it. It was to help prevent pinking and detonation.
I built a Westfield with a Honda S2000 engine in it. It was standard and designed for normal unleaded. It didnt justify the additional cost of super unleaded. Honda designed it to run on lower octane than we get at the pumps here. If I pushed it by tuning, with a supercharger etc, then I would have considered a better higher octane fuel.
I dont believe that the so called cleaners and performance gains are noticeable when used on my Zed , for the distance it travels .
A small snippet from a regular magazine write up............
Today petrol engines use similar anti-knock systems, but thanks to much faster processors in engine computers they can also use algorithms to predict when knock will occur. Naturally aspirated engines delay the point at which combustion is triggered (retarding the ignition) if knock threatens, all of which brings us back to the question of whether you need to fork out the extra dosh for super unleaded.
The answer is, there’s only one real reason to and that is because your car has a high-performance engine or the handbook explicitly says you should use it. Using fuel of a higher octane than your engine needs or can benefit from won’t hurt it, only your wallet.
The difference between premium and super unleaded at the UK forecourt these days is a maximum of two points (97 octane versus 99) and the chance of a modern engine being damaged by the lower of the two is nil.
I built a Westfield with a Honda S2000 engine in it. It was standard and designed for normal unleaded. It didnt justify the additional cost of super unleaded. Honda designed it to run on lower octane than we get at the pumps here. If I pushed it by tuning, with a supercharger etc, then I would have considered a better higher octane fuel.
I dont believe that the so called cleaners and performance gains are noticeable when used on my Zed , for the distance it travels .
A small snippet from a regular magazine write up............
Today petrol engines use similar anti-knock systems, but thanks to much faster processors in engine computers they can also use algorithms to predict when knock will occur. Naturally aspirated engines delay the point at which combustion is triggered (retarding the ignition) if knock threatens, all of which brings us back to the question of whether you need to fork out the extra dosh for super unleaded.
The answer is, there’s only one real reason to and that is because your car has a high-performance engine or the handbook explicitly says you should use it. Using fuel of a higher octane than your engine needs or can benefit from won’t hurt it, only your wallet.
The difference between premium and super unleaded at the UK forecourt these days is a maximum of two points (97 octane versus 99) and the chance of a modern engine being damaged by the lower of the two is nil.