Tire rolling resistance level (TRRL) means a value with units of kg/tonne that represents the rolling resistance of a tire configuration. TRRLs are used as modeling inputs under 1037.515 and 1037.520. Note that a manufacturer may use the measured value for a tire configuration's coefficient of rolling resistance, or assign some higher value.
40 CFR § 1037.801
The following definitions apply to this part. The definitions apply to all subparts unless we note otherwise. All undefined terms have the meaning the Act gives to them. The definitions follow: