The current European standard claims that all manufacturers = 2 kW must not exceed LWA95.
LWA95 is equivalent to 70 dB (A) at a distance of 7 metres.
We can say that dB (A) of 7 meters = LWA — 25.
dB (A) of 4 m = LWA — 20
dB (A) of 0 m = LWA — 0 = LWA
The sound level is dependent on the type of engine (petrol or diesel), the number of revolutions, and the cooling system. In general, we can say that:
- A petrol engine makes less noise than a diesel engine
- 1500 rpm is calmer than 3000 rpm
- A water-cooled engine is quieter than an air-cooled one