America’s Cars Are Suddenly Getting Faster and More Efficient

May 18, 2017, 06:00 PM

Sometime in the next couple of months, the Dodge Challenger SRT Demon and its 808 horsepower will show up in dealership windows like some kind of tiny, red, tire-melting factory. Yes, 808 horsepower. There’s no typo.

Teenage boys will lose their minds. Some older ones, too. But beyond the Vin Diesel fan club, it’s actually not such a big deal anymore. Last year, U.S. drivers on the hunt for more than 600 horsepower had 18 models to choose from, including a Cadillac sedan that looks more swanky than angry. Meanwhile, even boring commuter sedans are posting power specifications that would have been unheard of during the Ford Administration.

The horses in the auto industry are running free.

If a 1976 driver were to somehow get his hands on a car from 2017, he’d be at grave risk of whiplash. Since those days, horsepower in the U.S. has almost doubled, with the median model climbing from 145 to 283 stallions. Not surprisingly, the entire U.S. fleet grew more game for a drag-race: The median time it took for a vehicle to go from 0 to 60 miles per hour was halved, from almost 14 seconds to seven.

Four decades ago, there was one production car in America that made 285 horsepower–the Aston Martin DBS. It had a gaping maw of a hood vent and 75 more ponies than a Chevrolet Corvette. Today, more than half of the cars and trucks for sale boast as much power or more, including the milquetoast Kia Sorento. An Aston Martin Vanquish, meanwhile, makes 568 horsepower, almost double the grunt of its ancestor.

Sure, one would expect automobile engineering to advance over the decades just like any technology, but its acceleration of late would impress Don Garlits.

“It’s been wildly exciting,” said Bob Fascetti, head of powertrain engineering at Ford Motor Co. “If you go back and look at the degree of change in the last five or six years compared to the five or six before that or the five or six before that, it’s dramatic.”

Speed, of course, is a human condition, hard-wired into human DNA. The same atavistic spark that kept our ancestors safe among woolly mammoths also cooked up Dodge’s “Demon.” What’s even more remarkable, however, is that this combustion arms-race has occurred under ever increasing efficiency standards.

While vehicles have been getting more powerful, their engines have been shrinking. Moreover, the entire fleet is stretching a gallon of gas farther, thanks in part to electric engines.

Combustion engines on America’s roads are about 42 percent smaller than they were 40 years ago. At the same time, the EPA’s median measurement of miles-per-gallon has doubled, from 15 to 30. Most of those gains were made under pressure from federal efficiency mandates. The great power push began in 1985 just after the industry had hit a threshold of 27.5 miles-per-gallon.

Vehicles made another efficiency leap starting in 2007, when a new energy bill set a 35 miles-per-gallon threshold. This time, however, carmakers kept adding power.

How did engineers manage this sorcery? It wasn’t a single manufacturing breakthrough; it was about six of them. Consider the contemporary Chevrolet Camaro, which can be had with one of three different engines, each highlighting a major advancement in the race for efficient power.

The top-of-the-line V8, which makes 455 horsepower, is programmed to shut down four of its cylinders when they aren’t needed. Cylinder deactivation debuted about 10 years ago and is now standard in every eight-cylinder engine General Motors Co. makes.

It’s also put to use in the Camaro V6, the middle-of-the pack, Goldilocks choice that makes 335 horsepower. This machine highlights one of the most critical things in engine evolution: direct fuel injection. Carburetors that mixed fuel with air disappeared from assembly lines long ago. But it was only in the 21st century that engineers perfected the practice of shooting a mist of gasoline directly into the cylinder. Less fuel is wasted and the engine is more powerful because it stay...