But so far only a third of the country's filling stations sell ULSP and there are concerns that oil companies may be slow to make it more widely available or to pass on the tax cut . ULSP can be used in any car that already uses standard unleaded petrol and produces less sulphur dioxide.
Supporters claim it improves fuel efficiency too.
The Chancellor says ULSP will be available everywhere by the time of his spring Budget, when the full duty cut becomes effective. In fact, you may already have been filling up your tank with ULSP unwittingly. Esso, for example, says it is already selling ULSP in three-quarters of its filling stations, but pumps are labelled as unleaded. The Petrol Retailers' Association is warning that the oil companies could pocket the tax cut. The oil companies are concerned at the processing costs involved and at many filling stations ULSP has been selling at a 2p per litre premium over regular petrol.