‘It’s a waste of money’ – how premium petrol might actually be making your car run worse despite costing £6 more

A MECHANIC has revealed how premium petrol could be making your motor run worse despite costing £6 more than the standard stuff.

Scotty Kilmer, who has fixed cars for over 50 years, told YouTube viewers that pricier fuel is actually a "waste of money".

The motors whizz explained how most modern cars are actually set up to do their best work on lower-grade petrol.

Premium petrol, often known as super unleaded, includes higher quantities of the chemical component octane (hence why it is sometimes known as high octane fuel).

This allows the fuel to withstand a higher amount of pressure before it ignites to power the engine - this is called the compression ratio.

But, as Scotty explained, most engines these days do not require that higher compression ratio to work.

He said: "It's a waste of money putting premium fuel in a normal modern car.

"With modern engines having better design, lower compression and computer controls they will all run perfectly fine on regular fuel.

"If you have a car that's made for normal fuel and you put it in, it could actually run worse because it's set up for normal fuel at a lower compression.

"Just because premium fuel is more expensive, doesn't mean it's better for your car."

And that could end up saving you quite a bit of money in the long term thanks to higher prices for the premium stuff.

According to , normal unleaded is averaging 15.26p per litre while super unleaded sits at 163.09p.

Based on the average fuel tank, premium works out at around £6.50 more expensive per tank.

If you fill your car up every week, that could mean as much as £300 added to your annual bills.

However, Scotty did reveal one instance in which you might need premium fuel for a modern car and that is if you're running a high-performance model.

Using the example of a Ford Mustang, he added: "It will run just fine on normal fuel.

"But to get the full 300 plus horsepower, you need to use premium fuel."

Any car with a high-compression, powerful engine could see benefits from using super unleaded but it's not an absolute must.