Relating to a credit or refund for diesel fuel taxes paid on diesel fuel used in this state by auxiliary power units or power take-off equipment.

HB 1663 would allow businesses and individuals in Texas to claim a credit or refund for diesel fuel taxes paid on diesel used specifically for auxiliary power units (APUs, like those powering air conditioning without running the main engine) or power take-off (PTO) equipment on motor vehicles. The credit applies only to fuel used for these auxiliary purposes, not for climate control systems (e.g., passenger comfort) or idling. Claimants can use a separate meter to measure fuel usage or, if no meter exists, a percentage of total fuel consumption (determined by the state comptroller) to calculate the refund amount. The bill would take effect on September 1, 2025.