(1)If in the opinion of the Secretary of State the accuracy of any kind of indication of performance with respect to appliances of any description cannot be precisely guaranteed for individual appliances of that description, he may by order—
(a)apply the provisions of this section to indications of performance of the kind in question; and
(b)prescribe tolerances relating to any such indications of performance for the purposes of this section.
(2)An indication of performance to which this section is applied by an order under subsection (1) above shall not be treated as a trade description for the purposes of the [1968 c. 29.] Trade Descriptions Act 1968 if—
(a)it is given by means of a type approval mark within the meaning of Part I of this Act; or
(b)it corresponds with particulars approved for the model in question as mentioned in section 1(6) of this Act;
unless the performance of any appliance to which the indication relates falls outside the tolerances prescribed in relation to that indication.