We have all seen the additional fuel pumps at the petrol station. Often labelled with words such as Premium, Super, Ultimate and Momentum; these fuels promise to supply higher octane petrol or richer diesel but often come in at a higher price tag, which can be enough to put people off of buying it.
What are the differences between regular and premium fuels?
In the UK, the standard rating for petrol is 95 octane and every car sold in the UK has electronics in order to ensure that it can run properly on standard fuel. High octane petrols can range anywhere between 97 and 100 octane and tend to carry around a 10p per litre premium over regular petrol.
As well as making the most of your supercar’s performance, the higher octane levels in premium petrols help the engine to work effectively and prevents engine knocking. This is down to the fact that the engines in performance cars can feature a higher compression ratio - the difference in size of the combustion chamber between the cylinder's lowest and highest points.
Unlike premium petrols, premium diesels don’t often have a higher octane rating, this is because diesel engines don’t ignite fuel in order to create power. Instead, the premium diesels will feature chemicals which are designed to shift soot deposits and other types of build-up that form within the engine’s fuel system.
Is it worth paying extra?
If you drive a petrol supercar, performance car or even hot hatchback, the evidence does strongly suggest that the use of a high octane petrol will benefit your engine. Plus when running a performance car on a premium petrol, you should notice a difference in throttle response, amongst other things.
However, if you are driving any type of diesel car, a tankful of premium diesel will do it good roughly every 1,000 miles. By running premium diesel, you’ll be clearing out build-up from within the engine and fuel system; helping your car to be more efficient and economical when you switch back to regular diesel. Occasional use of a premium diesel can even help to avoid costly repairs in the future, as engine build-up can lead to your diesel engine packing up.
If you don’t like the thought of paying for high octane fuel everytime you fill your car up, using a regular petrol should be fine for your car, however for both petrol and diesel engines, your car will benefit from a tankful of premium fuel every now and then.
Worried that your car might need a high octane petrol? Most cars will have a label on the inside of the fuel filler flap, showing which type of fuel you should use in your car or failing this, there will be a note in the owner’s manual.