Should you buy the cheapest fuel, or will it damage your car?

Petrol prices have sky rocketed recently, with many drivers scrambling to save any way that they can, but what are the best options to take when you fill up your tank?

While E10 petrol is always cheaper than the unleaded alternative, it is not always the most cost-effective option. E10 is regular unleaded petrol blended with between nine and 10 per cent ethanol.

Because the E10 fuel is not as efficient, you will not get as far compared to filling your tank with regular unleaded.
,br>Natalie Roberts, the managing director of engineering group ABMARC, which conducts testing on fuels, believes you should only fill up with E10 if it is at least four cents per litre cheaper than regular unleaded fuel. If the price difference is any less than that, it will end up costing you more in the long run.

The situation is complicated further depending on the age of the car that you are driving. Because the ethanol content in E10 fuels increases the octane rating of the fuel, modern vehicles have an advantage that older cars do not.

“Higher octane can enable the engine management system on modern vehicles to optimise spark timing to suit the engine load and fuel grade, which will increase power and improve fuel efficiency in some circumstances,” Ms Roberts explained in an opinion article on

“For the folks driving modern vehicles, the small performance benefit provided by E10’s higher octane will help make up for the fuel’s lower energy content and on average their driving costs could end up the same as driving on regular unleaded.”

According to Ms Roberts, around 10.7 million Australian vehicles require regular unleaded fuel as a bare minimum and at least 40 per cent of these vehicles will not derive any benefit from the higher octane provided by E10 at current prices.

What fuel do you use in your car? Have you noticed a difference between using E10 and regular or premium unleaded petrol?

Written by Ben


How to have faith in financial planning advice

There is a way to rebuild trust in the financial planning sector, a peak body says.

Fake celebrity endorsement scams costing Aussies thousands

People are increasingly being caught out by celebrity endorsement scams.

Explained … how to compare superannuation funds

Super comparison websites can be useful in helping you to compare super funds.