Premium petrol & diesel: Are they worth it?

A burning question for many who take pride in their cars: are premium fuels worth the extra money?

Well, this will depend on a couple of things, most notably whether you are running a performance vehicle or not, while making cost-effective trips to the fuel station might be another.

You may have been at the pumps and stared for a second or two at the premium fuel option and wondered if it’s worth that extra cost per litre.

Here’s your guide to whether you should ever take the plunge and go premium.

What is premium petrol?

To know whether or not premium petrol is worth it or not, it’s naturally useful to get an understanding of what it is first.

Premium unleaded petrol is not massively different from the regular alternative – however, where it does differ makes an impact – if you have the right car.

All petrol types have a research octane number (or RON), and it’s the value of this octane number which matters. 

While a regular petrol will typically offer a RON of 95, a premium version will range from 96-99. Although higher octane fuels are harder to ignite, they will burn so much more effectively once they do.

As such, it can offer better performance from the engine and related components.

Meanwhile, premium petrol can also offer additives and detergents which will help keep the inside of the engine clean. Also, as fuel of a higher octane level can create the same power output with less volume, premium petrol can potentially be more fuel efficient than its counterparts.

So is premium petrol worth it?

So this is where we give a big fat ‘it depends’.

If you have a fairly normal car, premium petrol won’t really help you in any way, as it won’t have been designed to take advantage of a higher octane level – at best, you may see your fuel economy improve, but perhaps not enough to justify the extra outlay of a premium fuel.

However, if you’re running a performance car, it can be important to at least occasionally take the plunge on premium petrol so that you can maximise the potential of your vehicle.

Additionally, it might be that the car has been especially designed to run on a minimum octane level, and if run on anything less, it could damage the engine and surrounding components.

For anyone with a high performing vehicle wondering which fuel they should use, it should tell you on the inside of your fuel filler cap.

What about premium diesel?

Often referred to as ‘super diesel’, the premium version of petrol’s counterpart is a slightly different story.

With premium diesel, a higher octane rating doesn’t really come into the conversation, as diesel engines don’t ignite fuel to create their power; instead, fuel is added to the air that is compressed.

Where ‘super diesel’ comes into its own is when you consider the enhanced chemicals that feature in the overall mix.

These additional features to the diesel look to shift and clear soot deposits, along with other oily build-ups throughout the engine’s fuel system.

As a result, paying a bit extra every now and then tends to make premium diesel worth it, especially if you like to keep things under the bonnet ticking away nicely.