Because of the CAFE standards, which I posed above for light trucks.

Vehicles in general have gotten incredibly expensive in recent years. This E.O. strikes me as typical Trump “this is simple, I’ll fix it by decree” grandstanding. And I voted for him so don’t accuse me of TDS.

Regulation has done much harm to diesels, and EVs have been cost shifting to ICE vehicles (EVs get carbon credits paid for by those buying ICE).

CAFE rules have long fucked up small trucks and cars. That is part of why people moved to large trucks and SUVs. Personally I like the smaller Toyota trucks of yesteryear. CAFE rules have tended to restrict the smaller trucks more than the larger ones.

This reviewer does not think it will happen: https://insideevs.com/news/773876/slate-truck-live-impressions-china/

His review is interesting in that he comments on how much the “customization” philosophy is a part of Chinese car culture and Chinese manufacturers lean into that. That was always a big part of U.S. automotive culture through the 1970s. Boys (it’s mostly a male thing) want to repair their own vehicles and add personal touches.

I agree. And those little Toyota trucks also, or the Subaru Brat. It seems obvious, but no manufacturer does this.

A small, stripped down, cheap, rear wheel drive pickup. Americans would eat them up.

https://townhall.com/tipsheet/amy-curtis/2025/12/06/nyt-auto-regs-sat-n2667373

“Trump Was Right to Slam the Brakes on Fuel-Efficiency Standards”

In re the “legislating” observation (which is true, and applies to far too much of what passes for “law” in America), a commenter at the TH link notes that Ted Cruz has introduced a bill to codify the change, and points out that Trump’s Big Beautiful Bill already reduced the penalty for noncompliance with CAFE rules to 0.
Another one says the real savings would come from repealing the CARB rules, which I had to look up.

https://www.servicetruckmagazine.com/news/california%E2%80%99s-carb-rules-no-certificate-no-operation/
“California’s push for cleaner air has led to some of the strictest emissions regulations in the country, and truck operators are squarely in the crosshairs. Under the California Air Resources Board (CARB) rules, any diesel-fueled truck with a gross vehicle weight rating (GVWR) over 14,000 pounds must be CARB-compliant to legally operate within the state.”

More details at the post, but anything requiring re-engineering and retooling for new trucks, and outright banning any older truck that can’t be brought into compliance, will raise the prices of the “legal” vehicles
.
California is the tail that wags the dog in a lot of areas.