For engines in a lower state of tune, the higher octane really seems to make little difference either in bhp or mpg. However, where the benefit has been proven is with high performance engines.
Spot on Simon!
In Canada, we live 10 miles from the legendary Circuit (sir-kwee) Tremblant. During the summer season, race track fuel is sold by two stations and I keep my mog tuned for and full of 96 minimum (which translates to 102 Octane in European standards). The car's performance is sharp as a rapier. (Of course, mileage suffers.) When we go mogging, I detune the car to accept 92 Octane (aka 97 European). Noticeable difference.
Always use the highest octane you can find for a tuned car you use for fun. Snowmobiles are the best, you can change the fancier models from low tuning to high with the turn of key. Try that with 182 bhp on a 240 kilo machine!
Lorne
