Fuel — General Information and Savings (Audi A4 B6)

The engines require Euro Super unleaded fuel to operate (octane number 95), 3.0L engine runs on Super Plus (octane number 98). You can also fill up with normal gasoline (octane number 91), for 3.0 l engine Super fits (octane number 95). All fuel grades have the same quality. It is important that unleaded fuel meets the DIN EN 228 standard. The determining feature is the knock resistance. Knock resistance is determined by the octane number, Super gasoline has a higher octane number than normal gasoline. When using normal gasoline, engine power is slightly reduced.

If the octane number of the fuel available is lower than that required by the engine, the engine can only be operated at medium speeds and reduced load. High load (full throttle) or high revs may cause engine damage.

How to save fuel?

Move off immediately after starting the engine, including at sub-zero outside temperatures. Acceleration should be done at a pace, but shifting to the next higher gear should be done as soon as possible. After reaching the required speed, engage the highest possible gear, press the accelerator pedal as little as possible. The engine should run at high revs only when overtaking or changing lanes. In addition, turn off the engine even during a short stop at a railway barrier or traffic light, as well as in a traffic jam, since even five to seven seconds are enough to save fuel. When driving, assess the situation in a timely manner, do not brake unnecessarily.



Tire pressure can be increased by 0.1 bar, which reduces rolling resistance and saves fuel. Those who do not pay attention to tire pressure not only reduce their own safety, but also increase fuel consumption. If the tire pressure is 0.5 bar lower than prescribed, fuel consumption increases by 5%. So do not be lazy about pumping up your tires. To achieve the ideal pressure and save gasoline, you can inflate your tires with nitrogen.

Extra kilos in the trunk and other unnecessary cargo (roof rack) increase fuel consumption.

Optimising fuel consumption with the continuously variable Multitronic transmission

Optimum fuel consumption can also be achieved by choosing a continuously variable automatic transmission. Thanks to the use of state-of-the-art automatic control technology, Audi Multitronic not only achieves very good driving dynamics, but also excellent fuel consumption figures. Multitronic transforms the driver's wishes into the corresponding driving characteristics of the vehicle without any compromises, without compromising dynamics, comfort or economy. This is why this transmission can be considered the smartest link between the driver and the road to date.

Fuel related concepts

Normal gasoline and "super" gasoline. These grades of gasoline are almost identical in terms of the degree of purification and evaporation properties (important for flammability) and energy balance (heat of combustion per kilogram of fuel). An important difference is in detonation resistance, "super" gasoline is more resistant to detonation than normal gasoline.



Knock resistance. The higher the compression ratio, the easier it is for spontaneous combustion to occur in the cylinder if the fuel is not sufficiently resistant to detonation. "Super" gasoline can withstand higher pressure than normal gasoline, but it is more difficult to ignite. The fuel knock sensor, which is part of the engine management system, regulates the ignition accordingly. However, if you fill the tank with fuel with a lower octane number than recommended, you should take into account a decrease in engine power.

Octane number. The octane number determines the knock resistance of the fuel. At the gas station, you can often see the octane number value according to the research method, less often the specification according to the motor method is used. Previously, in Germany, the minimum requirements for unleaded fuel were prescribed by the German Institute for Standardization (DIN) in accordance with the DIN 51 607 standard. Currently, the European standard EN 228 is in effect.

Cetane number. The cetane number determines the flammability of the fuel. This relative number is determined in the laboratory. Easily flammable fuel is assigned a number of 100, and conventional fuel, which ignites with extreme difficulty, is assigned a number of 100 (methylnaphthalene), — the number 0. The cetane number shows what percentage of cetane (by volume) must be contained in a mixture with this standard fuel so that it has the same flammability as the measured fuel.

Fuel handling

Handling fuel is a dangerous business, so do not take maintenance and repair work on fuel system components lightly. Extreme caution must be exercised, especially when emptying the fuel tank. In general, the following safety precautions must be observed when handling fuel:

• First, disconnect the battery, protect the wire from touching the battery terminals.
• A powder, carbon dioxide or other liquid fire extinguisher should be on hand.
• Only empty the fuel tank in the open air. A suitable pumping device is required for this purpose (for example, a bellows pump with a hose). Never empty the tank through the fuel level sensor opening by tipping the tank or by sucking out fuel with your mouth through a hose - there is a risk of poisoning with highly toxic additives!
• Avoid contact with skin! You can wear fuel-resistant gloves for this purpose.
• Never empty the tank over an inspection pit. The gases that escape are heavier than air, so they can remain in the pit for several hours. This is dangerous to health, and there is an immediate risk of explosion.
• Make sure that there are no switched-on appliances, open flames, heat sources or sparks nearby when working with fuel.
• Fuel may only be poured into a sealed container with a clear corresponding label. For this purpose, there are special containers with protection against ignition and a lid with a pressure equalization device.
• After emptying, there are residual gases in the tank. These gases are also dangerous, so all work should be carried out with particular care!

This article was previously published on the resource: AUDIMANUAL.RU