What is the role of fuel additives?
Premium fuels are characterised by their high content of performance additives. What are these additives and what are they used for?
Performance, longevity, pollution.... Essential additives
The fuels distributed by specialised oil companies contain so-called performance additives. When added to gasoline and diesel fuels, these chemical compounds modify the characteristics of these fuels to improve engine performance and longevity.
Modern, compact and sophisticated engines are especially sensitive to certain problems such as fouling, which reduces engine performance and longevity, increases fuel consumption and the emission of carbon dioxide and pollutants. High-quality fuels with additives are probably the most effective in countering the negative effects of fouling, notably thanks to the detergent additives they contain (see the following paragraph). A premium fuel with additives can be used for both curative and preventive purposes.
A guide to fuel additives
The following is a list of the main performance additives found in high-quality fuels:
Anti-corrosion. Protects metal parts against corrosion and rust caused by water. Among other things, these additives help extend the life of the injection system.Antioxidants. Prevent the premature deterioration of stored fuel, thus limiting the formation of sediment or gum in fuel tanks or reservoirs.
Demulsifiers and water dispersants. Reduce the risk of water in fuel, which is known to cause premature wear and tear in injection systems and engines.
Detergents. Clean or keep clean the essential components of injection systems (such as injectors and intake valves) by removing the carbon deposits caused by incomplete combustion. TOTAL EXCELLIUM fuel detergents reduce the fouling of injectors and valves.
Friction modifiers. Reduce mechanical friction losses between metal parts (mainly in the cylinder or in the injection pump) and improve engine performance.
There are specific additives for diesel fuel. The main diesel fuel additives are:
Cold flow improvers. Improve the operability of cold diesel fuel by lowering the temperature limit for its use. Diesel fuel can crystallize or even freeze at very low temperatures. Vehicles parked outside at night are the most affected. It should be noted that there are also “extreme cold” diesel fuels capable of withstanding temperatures as low as -20°C.
Anti-foam. Reduces foaming when filling the tank. The accumulation of this foam makes it impossible to completely fill the tank, causing fuel to overflow from the tank opening and to spill onto the body of the vehicle and the user’s feet.
Procetane. Improves combustion by facilitating the auto-ignition of diesel fuel.
Reodorants. Make the smell of diesel fuel more pleasant and less intense.
What about additives sold separately?
Many fuel additives can be purchased in containers in stores. The driver then pours a measured amount of the additive into the vehicle’s tank before refueling. The list of available products is long: there are injector, particle filter, EGR valve and carburettor cleaners, additives to reduce fuel consumption, anti-smoke and degumming (antibacterial) additives, and even lead substitutes for vintage automobiles.
Why buy these additives separately when they can be added to your tank right at the pump? With few exceptions, such as for owners of older vehicles, choosing a high-quality fuel with additives is usually sufficient to maintain the health of the engine, since the fuel already contains all the necessary additives.