Article 4 Rates of duty for fuel substitutes
Paragraphs (2) to (4) below apply where, within the meaning of section 6A of the Act, a liquid as a fuel is set aside for a chargeable use with the consequence that a duty of excise is charged by virtue of that section, and paragraph (5) below applies where, within the meaning of that section, a liquid as a fuel is put to a chargeable use, not already having been charged under that section with a duty of excise, with the consequence that a duty of excise is charged on that use under that section.
Where a liquid is entered in the record as being suitable only as fuel for:—
a diesel engine, or an engine, other than a piston engine, of an aircraft, the rate of duty shall be that specified by section 6(1) of the Act for heavy oil;
a petrol engine powered by leaded petrol, the rate of duty shall be that specified by section 6(1) for light oil; and
a petrol engine powered by unleaded petrol, the rate of duty shall be that specified by section 6(1) of the Act for light oil less any rebate specified by section 13A of the Act for unleaded petrol.
Where a liquid is not entered in the record as being suitable only as fuel for one of the categories of engine described in the preceding paragraph, the rate of duty shall be the rate specified by section 6(1) of the Act for light oil, unless in respect of that liquid paragraph (4) applies.
Where the liquid mentioned at the end of the preceding paragraph is entered in the record as being specially produced as fuel for the piston engine of an aircraft and is delivered for use solely as fuel for the piston engine of an aircraft, the rate of duty shall be one half of the rate specified by section 6(1) of the Act for light oil.
Where a liquid is used as fuel in an engine described in subparagraph (a), (b) or (c) of paragraph (2) above, the rate of duty shall be that which is specified in that subparagraph; and, if the liquid is used in the piston engine of an aircraft, the rate of duty shall be that which is specified in paragraph (4) above.