New Mexico Statutes Chapter 7. Taxation § 7-15A-8. Mileage and weights to be used for computing tax

A. The total number of miles traveled on New Mexico highways during the tax payment period by the motor vehicle subject to the tax shall be used in computing the tax.

B. Registrants, owners and operators of all motor vehicles to which the tax applies shall report to the department, in the manner required by the department, the total mileage traveled in New Mexico and the total mileage traveled in all states during the tax payment period applicable to that registrant, owner or operator.

C. All motor vehicles subject to the tax shall be registered in accordance with law at the highest gross vehicle weight or combined gross vehicle weight at which the vehicle will be operated for that registration year in this state.

D. It is unlawful and a violation of the Weight Distance Tax Act for any motor vehicle to be operated on New Mexico highways at a gross vehicle weight higher than that at which the registrant declared for registration purposes pursuant to either the Motor Vehicle Code  1 or the Motor Transportation Act.  2 The operator of a motor vehicle operated on highways of this state at a gross weight or combination gross weight higher than that declared for registration purposes shall be subject to the penalty provisions of Section 66-7-411 NMSA 1978.