CO SB021

Expands the Clean Fleet Enterprise's authority to incentivize replacing diesel trucks (model year 2009 or earlier) with newer heavy-duty trucks (model year 2018 or later) through grants, rebates, revolving loans, and other financing strategies through December 31, 2031

Requires purchasers receiving enterprise funding to surrender their aging diesel truck to the seller, who must decommission it by drilling a hole in the engine block and cutting the chassis rails in half

Limits enterprise spending on the diesel truck replacement program to no more than 20% of the Clean Fleet Enterprise Fund's annual income

Applies to heavy-duty trucks over 26,000 pounds that are Colorado-based and part of fleets driving at least 75% of their annual miles in-state

Removes a January 1, 2027 restriction that would have limited compressed natural gas vehicle funding to situations where electric vehicles are not practically available