The NHTSA and EPA are closing in on their final rules for 2017-2025 corporate average fuel economy regulations, but there's a wild card in the pack.

California, which has the authority to set its own emissions laws, is going along with the proposed gas-mileage levels, which will take 2025 model-year vehicles to an average of 54.5 mpg (which translates to window stickers in the low 40s).

But in mid-November, the California Air Resources Board (CARB) announced that it would also require automakers to sell a certain percentage of zero-emission vehicles (known as ZEVs) in the state, on top of the national fuel economy rules.

The regulations were officially proposed yesterday, and the board will decide whether to adopt them in late January.

CARB's Advanced Clean Cars program for 2015 through 2025 (full details here) requires increasing numbers of cars that operate on grid electricity either part of the time (plug-in hybrids) or entirely (battery electric or fuel-cell vehicles).

2011 Nissan Leaf SL

2011 Nissan Leaf SL

It will no longer count cars powered by alternate fuels, including natural gas, under the zero-emission vehicle category. Today's natural-gas vehicles, including the 2012 Honda Civic Natural Gas, are considered ZEVs and qualify for single-occupancy use of freeway HOV lanes, among other incentives.

By 2025, the rules will require that one in seven cars sold in California (15.4 percent) be either a fully zero-emission or a plug-in hybrid vehicle. In that year, CARB expects to have 1.4 million such vehicles on California roads.

The effect, it says, will be to reduce greenhouse gas emissions by 40 million tons per year, equivalent to taking 8 million vehicles off the state's roads. And it will save $5 billion in running costs for drivers, since a mile driven on grid power costs just one-fifth to one-third what the same mile costs on gasoline today.

fcx clarity fuelcell motorauthority 002

fcx clarity fuelcell motorauthority 002

By 2040, the board expects the vast majority of new vehicles sold to be zero-emission. With standard fleet turnover, that means that by 2050, more than seven of every eight cars on the road in California are projected to be driven by electric motors powered either from batteries or fuel cells.

CARB has long been known to harbor a special fondness for hydrogen fuel-cell vehicles, and fuel-cell proponents greeted the new regulations with approval, noting that the board wants "major refiners/importers of gasoline" to be responsible for providing hydrogen fueling stations to the state's drivers.

Other clean-car advocates, including the Union of Concern Scientists, voiced their approval of the new regulations as well, though noting that still further reductions would be needed to get California's greenhouse-gas emissions down to where scientists suggest they should be by 2050.


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