Fuel additives are chemical substances that are mixed with fuel to enhance its performance or improve certain characteristics. These additives are designed to modify the properties of the fuel and optimise its combustion process. Here are some common functions and benefits of fuel additives:

1. Octane Boosters: Octane boosters increase the octane rating of petrol, which helps prevent knocking or pinging in high-performance engines. They allow the engine to operate at higher compression ratios, resulting in improved power output.

2. Fuel Stabilisers: Fuel stabilisers prevent fuel degradation and the formation of varnish and gum deposits that can clog fuel lines and injectors. They are particularly useful when storing fuel for long periods, such as in seasonal equipment or backup generators.

3. Detergents and Cleaners: Fuel detergents and cleaners help keep fuel injectors, valves, and combustion chambers clean by removing carbon deposits and other contaminants. This improves fuel atomisation, reduces emissions, and maintains engine efficiency.

4. Corrosion Inhibitors: Corrosion inhibitors protect the fuel system components from rust and corrosion caused by moisture and other impurities in the fuel. They are especially important for vehicles with steel fuel tanks and fuel delivery systems.

5. Lubricity Enhancers: Lubricity enhancers reduce friction and wear between moving parts, such as fuel pumps and injectors. They provide lubrication to components that come into contact with fuel, helping to prevent premature wear and extend their lifespan.

6. Cold Flow Improvers: Cold flow improvers are used in diesel fuels to prevent the formation of wax crystals at low temperatures. By modifying the fuel's properties, these additives lower the pour point and improve fuel flow, preventing fuel filter clogging and fuel line blockages in cold weather.

7. Anti-Foaming Agents: Fuel additives may contain anti-foaming agents to reduce the formation of foam during fuelling. Foam can lead to inaccurate fuel metering and can cause fuel spills when filling tanks.

8. Cetane Improvers: Cetane improvers are used in diesel fuels to improve ignition quality and combustion efficiency. They enhance the diesel fuel's ability to ignite easily and burn more completely, resulting in improved engine performance, reduced emissions, and smoother operation.

It's important to note that not all fuel additives offer significant benefits, and their effectiveness can vary depending on the specific circumstances and vehicle/engine requirements. It's recommended to follow the manufacturer's recommendations and choose additives that are compatible with your vehicle and fuel type.