I refer to the letter headlined, 'Cabbies penalised for using green fuel' (South China Morning Post, September 26) and would like to clarify that in general a diesel taxi will be saving fuel costs by changing to one using liquefied petroleum gas (LPG).

The Government conducted a comprehensive LPG taxi trial between 1997 and 1998 with the taxi trade and LPG taxi suppliers. One of the main objectives was to determine the cost of operating a typical five-passenger LPG taxi compared with its diesel counterpart. The trial confirmed that an LPG taxi would enjoy an operation-cost advantage. The LPG pump price will drop around the middle of this month. By then, the cost advantage will be more distinct and a typical LPG taxi should be able to save $100 to $150 dollars a day. On top of this, the Government is giving out a grant of $40,000 to each of the diesel taxis replaced by an LPG taxi. The use of an LPG taxi is thus extremely attractive.

The taxi referred by your reader is much bigger than a typical taxi and is equipped with engines about twice as large as other typical LPG taxis. There is no diesel taxi of equal size. A diesel taxi of this size would use much more fuel than a typical diesel taxi. Since different taxi owners may have different business plans and needs, some have chosen to buy these larger LPG taxis.