Can Californians afford cleaner cars?

The California Air Resources Board has pushed the envelope yet again.

The most aggressive clean air rule-making body in the country unanimously approved regulations last week that mandate car manufacturers cut smog emissions from new vehicles by 75 percent by 2025 and greenhouse gases by 34 percent.

To produce that level of emission reductions, CARB has set an ambitious target. The aim is that 15.4 percent of cars sold in California in 2025 will either be hybrids, which run partially on gasoline and electricity, or pure zero-emission vehicles powered by electric batteries or hydrogen fuel cells.

As CARB chairwoman Mary Nichols said after the vote, "This is really a historic new chapter in California's history with the automobile."

But the history-bending rules will do what they are designed to do — reduce pollution and cut greenhouse gases — only if the public buys the clean cars in the volumes predicted.

That's the big uncertainty.

As they implement the rules, regulators must do what the businesses they are regulating have to do — keep a sharp eye on the market and be prepared to pivot.

In past years, automakers have sued to block CARB rules. This time, somewhat reluctantly, they supported the rules. According to a spokeswoman for the Auto Manufacturers Association, car companies already produce 35 models of CARB-designated clean cars and they, too, want to see that market segment grow.

But market share for hybrids, electric, and fuel-cell cars is quite small, about 2.1 percent of all sales nationwide in 2011, and that is down from 2.7 percent in 2009.

The California New Car Dealers Association remains adamantly opposed to the rules. Dealers note that electric and hybrid vehicles on the market cost $11,000 to $13,000 more on average than comparable gasoline-powered cars.

Moreover, they require a change in consumer habits. Drivers will need to calculate how far they can go on a charge, for example.

Will the necessary infrastructure be in place, hydrogen fueling stations in the case of fuel-cell cars or charging stations for electric vehicles? And how long will it take to complete a charge or refuel with hydrogen? Also, success will depend on the price of gasoline. If it remains relatively flat or goes lower, sales of electric vehicles are likely to fall.

Roger Niello, a Sacramento car dealer, says he and his fellow dealers look at regulations from the "transaction level," where the customer meets the car. Holding on to inventory that does not move is costly in the loss of time and opportunity for profits from sales of vehicles customers want to buy.

The Obama administration has poured $2 billion of stimulus funds into trying to jump-start the electric car industry. The results have been mixed. Factories have been built and thousands of jobs created, but some companies that received stimulus funds have gone bankrupt.

The administration in Washington, like regulators in California, is waiting and hoping electric car sales eventually take off. The economy and the environment could use the lift.