Guide
Is premium fuel worth it?
Shell V Power, BP Ultimate and Esso Supreme cost several pence a litre more than ordinary petrol. For most cars that money buys you almost nothing. Here is when it is genuinely worth it.
Every big forecourt now sells a dearer petrol with a confident name, Shell V Power, BP Ultimate, Esso Supreme, promising a cleaner, healthier, more powerful engine. It sits a few pence a litre above the standard pump, which on a full tank is a real couple of pounds. The honest question is whether you get a couple of pounds of anything back. For most drivers, most of the time, you do not.
What you are actually buying
Premium petrol differs from standard in two ways. The first is octane. Standard unleaded is 95 octane, while the premium grades are 97 to 99. Octane is a measure of how well the fuel resists knocking under pressure, not a measure of power or energy. A higher number only helps an engine that is built to use it. The second difference is the additive package, the detergents and cleaners blended in to keep valves and injectors clean. The premium brands use more of these, and this, not the octane, is where any real benefit lives.
The cars that genuinely benefit
There are a few honest cases for paying more. If your handbook specifies a minimum octane of 97 or 98, your engine is designed for it and you should follow the manual, this is the one time premium is not optional. High performance and prestige engines fall into this group. Beyond that, a car that has covered a lot of miles on cheap fuel and is running a little rough can sometimes feel smoother after a few tanks of a premium grade, because the extra detergents clean deposits that have built up over the years. Think of that as an occasional service in a tank rather than a weekly habit.
Why it does nothing for an ordinary car
If your car is designed for standard 95 octane petrol, and almost every ordinary car is, feeding it 99 octane does not unlock hidden power. The engine simply cannot use the higher octane, so the headline promise of more performance never arrives in a way you would feel. The cleaning additives do something, but modern standard fuels already contain detergents that meet the legal standard, so the gap is smaller than the marketing suggests. Independent tests over the years have found real but small differences, nothing like enough to repay several pence a litre, week in and week out, in a car that does not need it.
The maths that settles it
Say premium costs seven pence a litre more. On a 55 litre tank that is close to four pounds every fill. Drive 10,000 miles a year in a typical car and you might buy forty tanks, so the premium habit costs you well over a hundred pounds a year. For that to pay back you would need a real and lasting improvement in economy, and for a car built for standard fuel it does not come. You would save far more, with no downside, by buying standard petrol at a cheaper forecourt.
The sensible rule
Use the fuel your handbook asks for. If that is standard 95 octane, buy standard and put the difference in your pocket, with perhaps the occasional tank of a premium grade if the car has done big miles and feels like it wants a clean. Then spend your attention where the real money is, the price of the forecourt you choose. Put your postcode into the price finder and it ranks every station near you by price, which will save you far more than any premium fuel ever could.
Common questions
Is premium petrol worth the extra money?
For most cars, no. Premium grades like Shell V Power and BP Ultimate help only engines designed for higher octane fuel, or an older high mileage car that benefits from an occasional clean. A car built for standard 95 octane petrol gets no gain you would notice, so the few pence a litre is wasted.
Does premium fuel give more miles per gallon?
Not in a car designed for standard petrol. Any improvement in economy is too small to repay the higher price. You would save far more by buying standard fuel at a cheaper forecourt than by paying for premium at any forecourt.
When should I use premium fuel?
When your handbook specifies a minimum octane of 97 or 98, because the engine is built for it, and optionally as an occasional clean for an older car that has covered big miles on cheap fuel. Otherwise standard petrol is the right choice.
What is the difference between premium and standard petrol?
Two things: octane and additives. Premium is 97 to 99 octane against the standard 95, which only helps engines designed for it, and it carries more cleaning detergents. Standard fuels already meet a legal detergent standard, so the real gap is smaller than the marketing suggests.