Premium Petrol vs Regular Petrol: Is It Worth Paying More?

With fuel prices remaining a significant expense for UK motorists, spending extra on premium petrol might seem like an unnecessary luxury. After all, if regular unleaded gets you from A to B, why pay more for something that appears to do exactly the same job?

But while premium petrol costs more at the pump, its higher octane rating and specialist additives promise improved engine performance, greater efficiency and potentially better long-term protection.

So, is premium petrol genuinely better for your car, or are most drivers simply paying extra for benefits they'll never notice?

We explore the differences between premium and regular petrol, whether the more expensive fuel can improve performance and fuel economy, and which cars actually benefit from using it.

What is premium petrol?

Premium petrol, often referred to as super unleaded, is a higher-octane alternative to standard unleaded petrol.

In the UK, regular unleaded typically has an octane rating of 95 RON (Research Octane Number), while premium petrol generally ranges from 97 to 99 RON, depending on the brand.

Popular examples include Shell V-Power, BP Ultimate and Esso Synergy Supreme+.

Beyond the higher octane rating, premium petrol products may contain additional detergent additives designed to help prevent deposits from building up within the fuel system.

These additives can help maintain fuel injector cleanliness and protect engine performance over time, although their effectiveness varies between products and engines.

Another important difference is ethanol content. Standard UK petrol is generally E10, containing up to 10% renewable ethanol, while super unleaded is typically E5, containing no more than 5%.

This makes premium petrol particularly relevant for some older vehicles that aren't compatible with E10.

However, a higher price doesn't automatically mean premium petrol is better for every car. Much depends on how the engine was designed.

What is an octane rating?

An octane rating measures petrol's resistance to engine knocking, a form of abnormal combustion that can occur when the air-fuel mixture ignites unexpectedly inside an engine.

The higher the octane rating, the greater the fuel's resistance to knocking.

In the UK, petrol is classified using its Research Octane Number, commonly abbreviated to RON.

Standard unleaded petrol is typically rated at 95 RON, while super unleaded is commonly available in 97, 98 and 99 RON formulations.

What is the difference between 95 and 99 octane petrol?

Although the numerical difference might seem small, higher-octane petrol can make a noticeable difference in engines specifically designed to take advantage of it.

High-performance petrol engines often operate with greater compression pressures, turbocharging or more aggressive ignition timing.

These conditions can increase the risk of engine knock, particularly under heavy acceleration or high engine loads.

Higher-octane fuel allows compatible engines to operate closer to their intended performance limits without encountering abnormal combustion.

However, in an everyday petrol engine designed for 95 RON, switching to 99 RON won't automatically deliver additional horsepower.

The engine must be capable of adjusting its operating parameters to benefit from the higher octane rating.

Why does engine knocking matter?

Engine knocking occurs when combustion doesn't happen in the controlled manner intended by the manufacturer.

Instead, part of the remaining air-fuel mixture ignites unexpectedly, creating pressure waves inside the cylinder.

Modern petrol engines use knock sensors and engine management systems to detect these conditions and adjust ignition timing to protect the engine.

While these systems are effective, repeated knocking can reduce performance and, in severe cases, contribute to engine damage.

For vehicles requiring higher-octane fuel, using the correct petrol is therefore important for both performance and engine protection.

Is premium petrol better for your engine?

Yes, but the benefits depend heavily on the engine, its condition and the type of driving you do.

One of the main advantages of certain premium petrol products is their enhanced detergent additive packages.

Over time, deposits can accumulate around fuel injectors and other components of the fuel system.

These deposits may affect fuel delivery and combustion efficiency, potentially contributing to reduced performance or increased fuel consumption.

Premium petrol additives are designed to help control these deposits and, in some circumstances, remove existing build-up.

However, standard petrol already contains additives and must meet the relevant fuel-quality requirements. Premium fuel is not essential for keeping a properly maintained engine healthy.

Petrol additives also have limitations. In direct-injection engines, fuel doesn't wash over the intake valves, so detergents in the petrol cannot directly clean deposits on those valves.

Ultimately, premium petrol may provide additional cleaning benefits, but it shouldn't be considered a replacement for regular servicing or proper maintenance.

Premium petrol vs regular petrol: benefits compared

Is premium petrol worth it?

For most everyday motorists, regular unleaded petrol offers the best value for money.

If your car is designed to run on 95 RON fuel, switching to premium petrol is unlikely to deliver a substantial improvement in acceleration, fuel economy or overall driving performance.

This means the additional cost at the pump can be difficult to justify.

However, the situation changes for drivers of high-performance vehicles, particularly those with turbocharged engines or engine management systems calibrated to take advantage of higher-octane fuel.

In these vehicles, premium petrol can help deliver the performance intended by the manufacturer.

There may also be a case for using premium petrol in older vehicles requiring E5 fuel or in cars whose manufacturers specifically recommend a higher octane rating.

For everyone else, the decision largely comes down to whether the potential cleaning benefits and small efficiency differences justify the additional expense.

Does premium petrol improve MPG?

Premium petrol can improve fuel economy in certain vehicles, but the difference is usually limited and isn't guaranteed.

Engines designed to take advantage of higher-octane fuel may operate more efficiently when using it, particularly under demanding driving conditions.

There's also a difference between E5 and E10 petrol. Because ethanol contains less energy per litre than petrol, E10 can deliver slightly lower fuel economy than a comparable E5 blend.

However, even if premium petrol provides a small improvement in MPG, that doesn't necessarily make it cheaper to use.

Using rounded UK average fuel prices:

At these prices, filling a 50-litre tank with premium petrol costs approximately £9 more than using regular unleaded.

To make up for that additional cost, premium petrol would need to deliver around 10.4% better fuel economy.

For example, if your car achieves 40 MPG using regular petrol, it would need to achieve approximately 44.2 MPG using premium petrol to offset the higher price.

For most vehicles designed to run on 95 RON petrol, that level of improvement is unlikely.

So, while premium petrol may offer certain performance or engine-cleaning benefits, regular unleaded will generally remain the more economical choice for everyday driving.

High-performance petrol cars

Some performance-focused vehicles are designed around higher-octane petrol.

This can include sports cars, high-output turbocharged engines and vehicles with more aggressive ignition and boost settings.

Depending on the manufacturer's requirements, using lower-octane petrol may cause the engine management system to reduce power or efficiency.

In vehicles where a minimum of 98 RON is specified, using 95 RON may be unsuitable unless the manufacturer explicitly permits it.

Older petrol cars

Older petrol vehicles may benefit from premium petrol for a different reason: ethanol compatibility.

Some classic cars and older models have fuel-system components that weren't designed for higher ethanol concentrations.

As premium petrol in the UK is generally E5, it can be a more suitable option for vehicles that aren't approved to use E10.

However, drivers should always check the manufacturer's guidance rather than assuming all older cars require premium fuel.

Remapped and modified petrol cars

Cars with performance remaps may be particularly sensitive to octane ratings.

Some engine tunes are specifically developed for 98 or 99 RON petrol, allowing more aggressive ignition timing or turbocharger boost.

Using lower-octane fuel in an engine mapped for premium petrol could reduce performance or increase the risk of knocking.

If your vehicle has been modified, always follow the fuel requirements provided by the tuner.

Does premium petrol make your car faster?

In some cars, yes. But don't expect premium petrol to transform an ordinary family hatchback into a performance car.

The main advantage of higher-octane petrol is its resistance to engine knock, which allows suitably designed engines to operate with more advanced ignition timing or greater boost pressure.

In a performance engine capable of adjusting these parameters, switching from 95 to 98 or 99 RON may improve power delivery and acceleration.

However, in engines calibrated exclusively for regular unleaded, higher-octane fuel typically provides little or no measurable increase in horsepower.

There's also a difference between gaining additional performance and restoring performance that has been lost.

If an engine is experiencing deposit-related issues, a suitable detergent additive package may help improve its operation over time.

But premium petrol won't repair worn components, fix mechanical faults or automatically increase an engine's maximum power output.

E5 vs E10 petrol: what's the difference?

One of the biggest differences between premium and regular petrol in the UK is their ethanol content.

Ethanol is a renewable alcohol blended into petrol to help reduce the fuel's overall greenhouse gas emissions.

The labels E5 and E10 indicate the maximum permitted ethanol content.

E10 became the standard grade of petrol in Great Britain in September 2021 and Northern Ireland in November 2022.

According to the Department for Transport, around 95% of petrol vehicles on the road at the time of its guidance were compatible with E10, including all cars manufactured since 2011.

However, some older vehicles, classic cars and certain motorcycles may not be compatible.

If you're unsure whether your vehicle can use E10, check the Government's official E10 compatibility checker.

Remember that E5 and E10 describe ethanol content, not octane rating. Although UK super unleaded is generally both E5 and higher octane, these are two separate characteristics.

Can you mix premium and regular petrol?

Yes, provided your vehicle is compatible with both fuels.

Mixing 95 RON regular unleaded with 97, 98 or 99 RON premium petrol is generally safe for cars approved to use 95 RON E10.

The resulting fuel mixture will have properties between those of the two fuels, depending on how much of each is added.

For example, topping up a half-full tank of regular petrol with premium petrol won't damage a compatible engine.

However, mixing the two won't guarantee the same performance benefits as filling up entirely with premium fuel.

If your car requires a minimum of 98 RON, adding regular unleaded could lower the mixture's octane rating below the manufacturer's requirement.

Similarly, owners of E10-incompatible vehicles should avoid mixing in E10 petrol simply because premium E5 is already in the tank.

Always follow your vehicle manufacturer's fuel recommendations.

What is the best premium petrol in the UK?

There are several well-known premium petrol products available at UK filling stations, each with a higher octane rating and its own additive formulation.

While no single fuel can be considered the best for every vehicle, the following are among the most recognisable options.

Shell V-Power Unleaded

Shell V-Power is a 99 RON premium petrol designed for engines that can benefit from higher-octane fuel.

It also contains a detergent additive package intended to help clean and protect key fuel-system components.

For drivers of performance-oriented vehicles requiring 98 or 99 RON, it's a widely recognised option.

BP Ultimate Unleaded

BP Ultimate is another premium petrol option, with a higher octane rating than standard unleaded.

It incorporates BP's proprietary additive technology, designed to help control deposits and maintain engine cleanliness.

It may appeal to drivers looking for a premium alternative without changing their usual filling-station brand.

Esso Synergy Supreme+ 99

Esso Synergy Supreme+ 99 offers a 99 RON formulation and an additive package designed to help maintain engine performance.

Like other higher-octane fuels, its greatest performance benefits are likely to be experienced in engines designed or calibrated to take advantage of it.

Tesco Momentum 99

Tesco Momentum 99 is a supermarket premium petrol with a 99 RON rating.

It provides a higher-octane alternative to standard supermarket unleaded and may appeal to drivers looking for premium fuel while using their regular supermarket filling station.

Other premium petrol options in the UK

Alongside Shell, BP, Esso and Tesco, several other retailers offer premium unleaded petrol at selected UK filling stations.

These include:

• Texaco Supreme Unleaded – a premium petrol option with cleaning additives, available at participating Texaco stations.
• Sainsbury's Super Unleaded – an E5 premium petrol alternative available at selected Sainsbury's filling stations.
• Costco Premium Unleaded 97 – a 97 RON petrol option available at participating Costco fuel stations, generally requiring a Costco membership.
• Gulf Premium Unleaded – higher-octane petrol available at selected Gulf filling stations.
• JET Super Unleaded – an E5 petrol option available at participating JET forecourts.

Availability and prices vary between locations, so check your nearest filling station before travelling specifically for premium petrol.

Premium petrol price comparison UK – October 2026

*Prices correct as of 30 October 2026. Figures represent reported UK average prices for premium unleaded (E5) at each retailer, based on UK Government Fuel Finder data published by FuelPriceAtlas. Prices vary between filling stations and may change daily. Individual premium fuel formulations may differ in octane rating and additives.

Which premium petrol should you choose?

The best choice depends on your vehicle's requirements, local availability and the price difference at the pump.

If your car requires a particular minimum octane rating, choose a fuel that meets or exceeds it.

Beyond that, there isn't enough independent, directly comparable evidence to confidently declare one premium petrol brand universally better than another.

Drive a diesel car? Discover whether paying extra at the pump is worthwhile in our Premium Diesel vs Regular Diesel guide.

So, is premium petrol worth paying more for?

For most UK motorists driving standard petrol cars, the answer is probably no.

Regular 95 RON unleaded is designed to meet the needs of the vast majority of modern petrol engines, and switching to a more expensive fuel is unlikely to produce dramatic improvements in performance or fuel economy.

However, premium petrol can be worthwhile for drivers of high-performance cars, vehicles requiring higher octane ratings, and older models that need E5 fuel.

Its additional detergent additives may also offer benefits in some engines, although these shouldn't be confused with guaranteed improvements in power, efficiency or reliability.

Ultimately, the best petrol for your car isn't necessarily the most expensive. It's the fuel that meets your manufacturer's recommendations and provides the best balance of performance, protection and running costs.

And if you're looking to improve your car's fuel efficiency without paying extra at the pump, don't overlook your tyres. Maintaining the correct tyre pressures and choosing tyres with suitable rolling-resistance characteristics can help reduce unnecessary fuel consumption.

For most drivers, those everyday maintenance decisions are likely to make a more dependable difference than switching to premium petrol alone.