In March 2010, an enthusiastic new owner of a 2005 H2 Hummer lauded the gas mileage he got out of his giant mammoth of a vehicle: 16 mpg. Yes, in some twisted world, getting 16 miles for every gallon of gasoline was once considered a triumph.

Luckily, the sun is setting on the gas-guzzling Hummer and its wide-berthed brethren. For the second time since taking office, the Obama administration has raised the Corporate Average Fuel Economy (“CAFE”) standards, which require all of the cars in a company’s fleets to meet a designated average gas mileage.

Three years ago the Obama administration raised that average to 35.5 mpg; but that number is being raised even further. Regulations finalized this week will force carmakers to produce fleets with vehicles that get an average of 54.5 miles per gallon by 2025. So any lineup with an H2 Hummer will need to include a car that gets upward of 100 miles per gallon to balance it out.

The administration estimates these higher standards will keep an extra $7,500 in a family’s pocket over the life of the car, and cut tailpipe emissions in half by 2025. President Obama called the new regulations “the single most important step” his administration has taken to break the American dependence on foreign oil.

Unsurprisingly, Mitt Romney has spoken against the standards, saying it will make cars and trucks more expensive. Though the administration admits the changes could force automotive prices up by $2,800 by 2025, it notes that lifetime gas savings will outweigh those additional costs.

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