Washington — Doubling fuel-efficiency standards to 54.5 mpg by 2025 won’t be cheap — and it will require the government to consider other implications.

The Obama administration finally unveiled the price tag to the auto industry for its proposed 2017-25 fuel economy regulations on Wednesday: $157.3 billion. But it will save consumers billions at the pump — and even billions more in time saved filling up at the pump.

In total, drivers will save $1.7 trillion at the pump — including the 2012-16 fuel increases. That’s far more than the costs of more expensive autos — and society will see net benefits of $252 billion to $358 billion.

But the administration said the savings at the pump will wipe out about $50 billion in gas tax revenue — and the government will have to find another way to fund road repairs.

It’s one of the most expensive — if not the most expensive regulation in U.S. history.

The hike — outlined in a nearly 900-page proposal — comes on top of the $51.5 billion price tag for 2012-2016 rules that boosted by more than 30 percent requirements to a fleet-wide average of 34.1 mpg by model year 2016.

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