Effect of Fuel Composition on Diesel Engine Noise and Performance

There is concern in Europe and elsewhere that present fuel quality for diesel engined road vehicles cannot be maintained with changing patterns of demand and utilisation of crude oil. In particular, the oil industry (in the UK) has asked for a reduction of the present British Standard of 50 cetane number minimum for such fuels.

Eleven diesel fuels with cetane number ranging from 26 to 58 and made from blends of gas oils refined from crudes from the Middle East, North Sea and West Africa were selected for test. The effect of these on noise and performance has been determined for three representative engines, IDI, DI and turbocharged DI.

The test results show that the relation ships between the various engine parameters measured and the basic fuel properties such as cetane number and specific gravity are not simple. Cetane number appears only to be valid when comparing fuels of similar chemical composition or at the same air temperature. Overall activation energy is tentatively suggested as a substitute for cetane number.