Steven Mayer pointed out in his May 15 article "Feds, state provide millions to clean up diesel trucks, tractors — but is it enough?" that funding for newer heavy-duty trucks in California is insufficient to achieve "the magnitude of emissions reductions required for attainment."

The world looks to California on environmental policy. So how shameful is it that our state is among the bottom five when it comes to the adoption of the latest clean commercial vehicle technologies?

California’s fleet of trucks and buses is much older than in 46 other states. The relative age of these vehicles translates into a higher-than-average amount of tailpipe emissions from big-rigs and buses on our roads.

Replacing these older trucks and buses with anything new – clean diesel, natural gas, EV, gasoline – will reduce emissions. But, a greater number of these old vehicles can be replaced using new clean diesel, meaning more emissions can be eliminated in total.

Unfortunately, the California Air Resources Board has chosen to invest California’s $423 million from the Volkswagen settlement in the most expensive bus and truck technologies, replacing the fewest number of trucks and buses and leaving lots of emissions on the table.

San Joaquin Valley residents would be better served if CARB prioritized clean diesel replacements for older, heavy-duty trucks. These are the largest source of emissions in California, and no other technology competes with the latest generation of diesel technology in efficiency, power, performance, and the ability to cheaply reduce NOx emissions.

Tom Fulks, Morro Bay