Five myths about premium fuel, busted
Premium fuels promise cleaner engines, more power and better economy. Some of that is real and some of it is forecourt marketing. Here are five common claims, weighed honestly.
Myth 1: premium always improves MPG
For most cars, no. Unless your engine is designed to exploit a higher octane, you are unlikely to see a measurable economy gain that justifies the price premium. High-performance engines that specify premium are the genuine exception.
Myth 2: it cleans your engine overnight
The detergents in premium and some branded fuels can reduce deposits over time, but it is a gradual housekeeping effect, not an instant flush. An occasional tank is more "regular maintenance" than "deep clean".
Myth 3: more octane is always better
Octane is about resistance to knock, not raw quality. Putting high-octane fuel in an engine tuned for regular octane usually does nothing useful. Match the grade to what your handbook specifies.
Myth 4: premium is a different product entirely
The base fuel still meets the same national standards. The differences are in additives and octane, not a secret better petrol. That is worth remembering when the price gap is several pence.
Myth 5: cheap fuel harms your engine
Standard supermarket fuel that meets the required specification is fine for everyday driving. The bigger lever for engine health is regular servicing and clean filters, not the brand on the canopy.
