Premium vs Regular Fuel: The Real Cost Difference for UK Drivers

When you choose premium petrol or diesel instead of standard fuel, the extra cost adds up fast. Even a modest 15p-a-litre premium adds £6 to every 40-litre fill-up, working out at well over £100 a year for drivers filling up twice a month.

For most cars, premium fuel brings minimal benefits so, at a time when all of us are trying to keep costs down wherever possible, sticking to standard E10 petrol or B7 diesel is the budget-friendly choice.

How Much More Does Premium Fuel Cost Right Now?

The table below shows the current average cost per litre of regular and premium petrol and diesel at UK fuel stations, drawn from our live pricing data.

The pence-per-litre gap shown in the table above is the number to focus on. Even a modest pence-per-litre difference can compound into a meaningful annual cost, especially for drivers filling up twice a month or more.

What Does That Mean for Your Wallet?

The tables below show the current cost of filling a full tank with regular and premium petrol and diesel for six of the UK's most popular vehicles, using our live price data.

To work out the annual cost for your own vehicle, multiply the per-litre price difference shown above by your tank size, then by how many times you fill up each year.

Fill up twice a month with a 40-litre tank and even a 15p/litre premium adds up to £144 a year.

With a larger 55-litre tank like a Range Rover Sport and a bigger price gap, the annual figure can approach £650.

Tank cost figures are based on filling from empty to full using current average prices. Actual costs will vary depending on vehicle, fuel station and location. All prices are updated regularly from our live fuel price database.

Can I Shop Around to Get a Better Price on Premium Fuel?

Shopping around makes a bigger difference than many drivers realise: the gap in price for the same grade of fuel between a branded station and a supermarket forecourt can be as large as the gap between regular and premium at a single station.

The tables below show current average prices by fuel provider, so you can see where you're likely to save the most.

If your car genuinely needs premium fuel, buying it at a supermarket station rather than a major branded forecourt is one of the simplest ways to reduce the cost. Even saving 10p per litre on premium fuel adds up to around £100 a year for a driver filling up twice a month.

How Much Does Premium Fuel Cost Near Me?

Fuel prices vary more by location than many drivers expect. The tables below show current average prices for regular and premium fuel across 10 major UK cities, so you can see how your area compares.

City-by-city variation can be significant, and in some locations the premium gap runs several pence per litre wider than the national average. For a driver filling up regularly, that difference in where you live can meaningfully change the annual cost of choosing premium.

Whether you're after regular or premium, the cheapest option near you is worth checking before you fill up.

What is Premium Fuel?

Premium fuel refers to super unleaded (E5) or branded premium diesel (B7+), covering products like Shell V-Power, BP Ultimate and Esso Synergy Supreme+.

The key difference for petrol comes down to the octane rating: standard unleaded (E10) has a Research Octane Number (RON) of 95, while premium fuels typically offer 97–99 RON. Octane isn't a measure of energy — it's a measure of a fuel's resistance to 'knocking', which happens when the air-fuel mixture in an engine's cylinder ignites prematurely, before the spark plug fires. Think of it like a pressure cooker releasing steam before the valve is ready: the timing is off, and in severe cases, it can damage the engine.

Engines with high compression ratios, found in many high-performance and sports cars, are more susceptible to knocking when run on standard 95 RON fuel. They're designed and calibrated to run on a higher octane, and that's where premium petrol genuinely earns its price.

For diesel, the mechanism is different: premium diesel products contain enhanced cleaning additives, higher concentrations of detergents designed to remove carbon deposits from injectors and the fuel system over time. This is a maintenance benefit rather than a performance one.

Does Premium Fuel Actually Make a Difference?

This is where the marketing tends to get ahead of the evidence. Fuel brands invest significantly in promoting their premium products, and the claims can sound persuasive. The reality depends heavily on your engine.

Fuel industry estimates suggest a marginal fuel economy improvement of up to 2-3% for engines built to take advantage of a higher octane rating. That's a genuine gain, but only for engines designed to exploit it. In most UK cars designed to run on standard 95 RON, the engine cannot adjust its timing to extract more from the higher-octane fuel, so the benefit simply isn't there.

To break even on premium petrol at a 15p/litre premium, you'd need a fuel economy improvement of around 9–10%. This is nearly four times what even the most optimistic industry estimate suggests you'll get. For most cars, the realistic gain is closer to zero.

Premium diesel works differently: the main benefit is injector cleaning over time, not a performance improvement on every tank. Some mechanics recommend running a tank of premium diesel through every 1,000 miles or so, not as a regular habit, but as a maintenance measure to keep injectors clear. For a high mileage driver, this occasional cost is more justified, given the long-term benefits it brings.

Does Your Car Actually Need Premium Fuel?

Before dismissing premium fuel entirely, it's worth asking one question first: does your car actually need it?

Check your fuel filler cap or your owner's manual. If it states '97+ RON', '98 RON required' or 'super unleaded only', your engine is calibrated for a higher-octane fuel and you should use it. On standard 95 RON, the knock sensor retards the ignition timing to prevent damage, which actually reduces power and efficiency. For these drivers, premium fuel is a requirement, not an option.

A second group of drivers has no choice at all: anyone with a vehicle made before 2011 that isn't E10 compatible. When the UK transitioned to E10 as the standard unleaded grade in 2021, older vehicles with fuel systems not designed for higher ethanol content, including rubber seals, fuel lines and carburettors, became incompatible. Super unleaded is E5, containing just 5% ethanol compared to E10's 10%, making it the only safe petrol option for many classic and older cars.

You can verify your vehicle's E10 compatibility on the government's E10 compatibility checker.

Who Does Premium Fuel Benefit?

Premium fuel genuinely makes sense for:

●      High-performance and sports car owners whose vehicles are designed to run on E5 or B7+ (check your owner's manual or fuel filler cap for the RON specification)

●      Drivers with turbocharged petrol engines where 97+ RON is recommended, since many modern turbo engines see a small but measurable improvement in power and efficiency from higher-octane fuel

●      High-mileage diesel drivers who use a tank of premium diesel periodically as an injector maintenance measure, rather than as their standard fuel

●      Owners of classic or older vehicles manufactured before 2011 that are not E10 compatible and need E5 super unleaded as their regular fuel

For the majority of UK drivers running everyday petrol or diesel cars, premium fuel is an unnecessary cost. It won't meaningfully improve your MPG, engine performance or long-term engine health if your car isn't built to benefit from it.

If My Vehicle Needs Premium Fuel, How Can I Keep Costs Down?

If your car genuinely requires premium fuel, there is still plenty of room to reduce what you spend.

Jessica Ruddick, Chief Marketing Officer at BookMyGarage, explains: "Although it may seem more convenient to fill up at the petrol station round the corner or on your way to work, shopping around for the best price on premium fuel is a great way to keep costs under control. In fact, understanding where the best prices are each day can help you save up to £5 a tank.

"If you fill up twice a month, this simple habit can save you nearly £120 a year. For many drivers, this goes a long way towards their annual MOT & service costs or annual road tax."

Where Can I Compare Fuel Prices Near Me?

Our free fuel finder tool shows live prices for regular and premium petrol and diesel at local stations, updated daily. Log in or create a free MyGarage account to find the best price in your area in seconds.

The Verdict on Premium Fuel

For most UK drivers, standard unleaded or diesel remains the cost-savvy choice.

Premium fuel offers real benefits for a specific group: drivers of high-performance cars calibrated for a higher octane rating, turbocharged engines where it's recommended, high-mileage diesel drivers using it for periodic injector maintenance and owners of older vehicles incompatible with E10 petrol. For everyone else, the extra cost delivers very little in return.

The most useful step any driver can take is straightforward: check the fuel filler cap or owner's manual. If it doesn't say 97 RON or above, standard unleaded is everything your engine needs.

Jessica has this advice for drivers considering their options: "At a time where we're seeing many drivers looking to cut costs wherever possible, choosing regular petrol or diesel instead of premium alternatives may be your smartest choice.

"Unless your vehicle needs premium fuel as specified by the manufacturer, you're unlikely to see enough benefit to justify the actual cost."

Fuel price data is sourced from BookMyGarage's live fuel price database and updated regularly. Costs shown are national averages and will vary depending on your specific vehicle, chosen fuel station and location. Per-vehicle fill-up figures are based on filling from empty to full and should always be used as a representative figure.