Unleaded 95 Gasoline can be used in practically all gasoline engines (2-stroke and 4-stroke). However, some older engines require a lead replacement component to maintain the lifespan of the valve seats.

In a gasoline engine, you do not want the fuel to self-ignite. The octane number indicates the fuel's ability to resist such self-ignition and is therefore an important quality parameter. Octane rating is measured, among other methods, using RON (Research Octane Number). 95-octane gasoline sold in Norway means it has an octane rating of 95 RON. For 98-octane, the octane rating is 98 RON. If an engine is run on gasoline with an octane rating that is too low, the petrol vapor in the combustion chamber can self-ignite from the heat of compression instead of from the spark from the spark plug. This is called engine knocking or pinging.

A common misconception is that the octane rating of the gasoline indicates the amount of energy in the fuel or that the engine delivers more power the higher the octane rating used. The truth is that gasoline contains the same amount of energy regardless of the octane rating.