Fuel Additives – What Are They and Do They Work?

Fuel additives are used in addition to the fuel you would normally use to run your vehicle on. They can either be bought separately or incorporated by the supplier at the pumps. Supplementing your fuel with additives is designed to give you better performance over standard petrol or diesel; however there is much speculation over the effectiveness of these products.

What do fuel additives claim to do?

The variety of fuel supplements on the market today are all boasting to be able to increase your acceleration and engine performance, restore lost horsepower as well as reducing your petrol consumption from prices ranging from £5 to over £20.

A common benefit cited amongst most of these products is their ability to fend off grime and other deposits which, over the life of your vehicle can build up causing problems and reduced efficiency and performance.

Types of fuel additives

Over the counter, fuel supplements will vary a lot in what they claim to offer you, so if your planning to give them a go, it’s important to know what you are looking for, so you get the results you are after.

Most fuel additives will fall into one of three categories. Those that will help to maintain the current condition of your car, those that will improve efficiency, saving you money on fuel and those that are used to enhance performance. You can also get ones that help to increase the longevity of your engine if you’re putting it into storage or won’t be driving it for a while.

Fuel efficiency

Fuel efficiency additives normally work by cleaning out the engine and parts to help improve the efficiency of the fuel. If there’s less residue in the engine, the fuel can work a lot better and will improve your overall performance. If an additive claims to increase your fuel economy or octane rating, steer clear as tests by independent authorities have shown that none do what they claim and some can increase the cost of filling by 50p per tank.

Vehicle performance

As well as cleaning the engine, some fuel additives can also help to stop diesel congealing, and in colder countries, it will get the engine to start quicker. You can also get lead-replacement additives if you have a leaded engine that hasn’t been converted over to unleaded.

Ongoing care

As with any fuel additive, many claims to clean the engine from carbon build up and other nasty substances that can decrease your vehicle’s efficiency and hinder its ability to run effectively. Some premium fuels also claim to do this, with many premium fuels optimising the cleaning of the engine as their main priority.

Do fuel additives actually work?

It has been suggested that these products may make improvements to a more performance oriented engine and that the additives found in super unleaded and premium diesel do have some benefit. However, apart from the higher octane that higher performance vehicles require, the average vehicle won’t see any difference between premium fuels or off-the-shelf additives. Using a fuel additive two or three times a year in an average car will help to clean the car and maintain longevity, but unless you drive a high-performance sports car, you won’t need to use a fuel additive every single journey. Like our advice on performance fuels, a use every six months, after a long journey or a long period in storage may help the car to recover and perform at best standard.