Many higher-performance engines require petrol with a higher octane rating, which produces a bigger “bang” inside the engine than normal fuel and therefore drives the engine harder.

Regular unleaded petrol (ULP) has an octane rating of 91 RON (Research Octane Number) while the more expensive PULP in Australia is 95 or 98 RON.

You can still use normal unleaded in cars requiring PULP, but not for extended periods and you should not use maximum performance.