Rounding of emission measurements.

(a) Unless otherwise specified, the results of all emission tests shall be rounded to the number of places to the right of the decimal point indicated by expressing the applicable emission standard of this subpart to one additional significant figure, in accordance with 40 CFR 1065.20. (b) Fleet average NO X value calculations, where applicable, must be rounded before comparing with the applicable fleet average standard and calculating credits generated or needed as follows: manufacturers must round to the same number of significant figures that are contained in the quantity of vehicles in the denominator of the equation used to compute the fleet average NO X emissions, but to no less than one more decimal place than that of the applicable fleet average standard. [64 FR 23925, May 4, 1999, as amended at 65 FR 6864, Feb. 10, 2000; 79 FR 23728, Apr. 28, 2014]