There are no shortage of premium fuels offered to you when you fill up your tank. But do the benefits they offer merit the extra price you pay?
What is premium fuel?
Often referred to as ‘super’ or ‘high performance’ fuel, premium fuels have a higher-octane rating than other fuels also offered at the pumps.
What is high octane fuel?
A high-octane fuel is usually harder to ignite because it requires greater compression to do so than lower octane fuels
The higher the octane rating, the less likely the petrol is to explode under pressure.
High-performance engines typically compress their fuel more. By using higher octane fuel, you’re able to avoid unexpected explosions that might damage your engine.
Standard fuels typically have a 91-95 octane rating whereas premium or super fuels have a rating of around 98-99.
You can also buy premium fuel diesel vehicles too – these come with a higher cetane rating.
Whether you’re filling your tank with higher octane or cetane fuel, the usual reason for doing so is to increase efficiency and improve performance.
How do you know if premium fuel is suitable for your car?
Your car handbook should provide you with details on the recommended octane (or cetane) rating for your engine.
The information might also be included in the casing around your fuel cap.
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What is super unleaded fuel?
Super unleaded fuel is typically a higher-octane version of regular unleaded fuel.
This means it has a higher-octane rating. Ordinary unleaded usually has an octane rating of around 91 Research Octane Number (RON).
Super unleaded usually has a rating between 97 RON and 99 RON.
The octane number is what you should focus on as the labels ‘Premium’ ‘Supreme’ ‘Super’ ‘Ultra’ can be quite confusing and not always mean the same thing.
What brands of premium fuel are on the market?
There are several brands available at UK petrol stations.
BP offers Ultimate Unleaded and Ultimate Diesel
Shell offers Shell V-Power
Texaco has developed its Supreme Unleaded 97
Total has Excellium Unleaded
In 2020 Esso launched its Synergy Supreme+ 99 fuel.
Does my car require a certain fuel type?
All cars must use a specific fuel type – which might be unleaded E5 or E10 petrol, diesel, Liquefied Petroleum Gas (LPG) or increasingly these days, electric battery.
Those of us who’ve put diesel in a petrol car or petrol in a diesel car will testify that fuel types don’t mix very well!
But assuming you put the right type of fuel in your car, does it matter if you choose the high-performance fuel version or not?
And what happens if you mix premium fuels with standard fuel that’s already in your tank?
Mixing standard unleaded petrol with a ‘Supreme’ or ‘Ultimate’ unleaded premium fuel is unlikely to do your engine harm.
Is premium fuel better for your car?
The producers of premium fuels insist that they provide noticeable benefits – notably that they remove dirt from the inside of the engine and help it to run more smoothly.
Some cars run optimally on standard unleaded fuel, while others run more efficiently on higher octane fuels like super unleaded.
This is why it’s worth checking your car manufacturers’ handbook for guidance on fuel.
It is perfectly fine to use a higher-octane fuel than the manufacturer recommends for your car – though it’s unlikely to offer any discernible benefit.
The only guarantee is that it’ll cost you more. However, using a lower-octane fuel than your car manufacturer recommends could result in engine damage over the long term.
If you own a high-performance car, the manufacturer might insist you use a premium fuel to ensure maximum driving performance and fuel efficiency.
How much does premium fuel cost?
You won’t be surprised to hear that premium fuel costs notably more than its regular alternative.
As of end of June 2021 regular unleaded could cost you around 132p a litre and regular diesel could cost 135p.
This compares to premier fuels such as BP Ultimate Unleaded costing around 144p per litre and Ultimate Diesel costing around 147p.
In this instance, we’re talking about a price difference on unleaded fuel of 12p per litre compared to the premier fuel option. Fuel prices may vary depending on the provider and region.
In some instances the gap between regular and premium fuel options could be as much as 20p per litre or more.
On a full tank of fuel, the price differential can really hit the pocket.
Is paying extra for premium fuel worth it?
Whether it's worth the extra cost is debatable. Certainly, for someone driving a small-to-medium sized engine, using premium fuel regularly is a waste of money.
It won’t provide extra power or speed – it just costs you more at the pumps.
It’s true that some high-octane fuel have cleaning qualities, which could improve the efficiency of older engines that have run on regular unleaded for years.
With this in mind, a tank of high-octane petrol might be beneficial once in a while. The fact is that the vast majority of cars function perfectly well on 95-octane standard unleaded fuel.
However, a few high-performance sports cars benefit from using premium fuel – in terms of improved performance, engine protection and greater fuel efficiency.
If you think your car might benefit from high-octane fuel and the manufacturer suggests it as an option – try it out for yourself. If you can’t really see any improvement in fuel efficiency or performance, it’s probably fine to take the regular fuel option.
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Should you fill your second-hand car with premium fuel?
This all depends on what type of second-hand car you have. There’s a big difference between a high-powered Porsche and a 1.2 litre Ford Fiesta!
If the Porsche has been filled regularly with premium fuel and drives like a dream – maybe there's a good argument for sticking with it.
Similarly, if you drive a less-powered vehicle you could flush through a few tanks full of premium fuel to clean out the engine.