Tex. Tax Code § 152.0215

(a) Except as provided by Subsection (a-1), a surcharge is imposed on every retail sale, lease, or use of every on-road diesel motor vehicle that is over 14,000 pounds and that is sold, leased, or used in this state. The amount of the surcharge for a vehicle of a model year 1996 or earlier is 2.5 percent of the total consideration and for a vehicle of a model year 1997 or later, one percent of the total consideration.

(a-1) The surcharge does not apply to a recreational vehicle, as that term is defined by Section 522.004(b), Transportation Code, that is not held or used for the production of income.

(b) The surcharge shall be collected at the same time and in the same manner and shall be administered and enforced in the same manner as the tax imposed under this chapter. The comptroller by rule shall adopt any additional procedures needed for the collection, administration, and enforcement of the surcharge authorized by this section and shall deposit all remitted surcharges to the credit of the Texas emissions reduction plan fund.

(c) This section expires on the last day of the state fiscal biennium during which the Texas Commission on Environmental Quality publishes in the Texas Register the notice required by Section 382.037, Health and Safety Code.