The Race to Revolutionize Your Car’s Engine
Business + Economy

The Race to Revolutionize Your Car’s Engine

© Robert Galbraith / Reuters

Carmakers are in a race against the clock. By 2025, every automaker's fleet must average 54.5 miles per gallon, 60 percent better than today’s vehicles.

Electric and hydrogen-powered fuel cell vehicles may help, but they likely won’t get manufacturers all the way to that goal. So even as carmakers show off those environmentally friendly vehicles at the North American International Auto Show starting this week in Detroit, they and their suppliers are turning to technologies that can improve fuel economy in traditional internal combustion engines. In other words, most of the cars of the foreseeable future will be like today’s: powered by gas.

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"There is still some life left in the internal combustion engine" and room to improve its efficiency, said Karl Brauer, senior analyst with Kelley Blue Book. "It's still the most cost-effective way to move people around. There's no reason to abandon that engine yet.”

Carmakers have been looking for cost-effective ways to meet tougher gas mileage standards, especially with consumers buying bigger, less efficient vehicles now that gas prices have plummeted. Sales of small, midsize and large sedans fell by roughly 11 percent from 2014 to 2015, according to Michelle Krebs, a senior analyst at, while pickup trucks and SUVs were up 15 percent.

At the same time, the market share for electric vehicles — which have the best fuel economy of all cars — fell to 2.8 percent, one percentage point off the 3.7 percent peak in 2013. That’s despite generous incentive programs and a larger choice of brands and vehicles, according to

Improving on gas-powered engines is also less expensive than building a car that runs on a more revolutionary power train. “Electrification is an expensive way to go," said Dan Nicholson, vice president of General Motors Global Powertrain.

Already, there are gas-powered cars in Europe that exceed the 2025 standard, said Mike Stoller, director of communications at Honeywell, a major automotive supplier. And the U.S. market is seeing fuel economy gains. Several cars sold in the U.S. made's "30 MPG Club," including the Ford C-Max Energi and the Mitsubishi Mirage. The BMW 3 Series gets a combined city/highway of 37 mpg, while a Hyundai Sonata Eco four-door sedan gets 32 mpg.

Carmakers are adopting a handful of technologies to further improve the efficiency of internal combustion engines, with many of the new features widely available in models on display at the North American International Auto Show starting this week in Detroit.

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A technology called stop-start involves shutting the engine down when it's not in use to avoid the efficiency losses that occur when a car is idling, like at stop lights or in traffic. The technology can result in fuel economy savings of roughly 2 percent. J.D. Power estimates that stop-start be in 38 percent of North American cars by 2019, compared with about 8 percent today.

The transition, though, has been far from perfect. The early systems drew criticism from customers who said it felt like the car was stalling at the stoplight, then shaking when the engine restarted. But Brauer says the technology has since been refined so consumers won't even be aware it's in their car.

Stop-start also isn't ideal in slow-moving traffic in major cities like Los Angeles, but it works well in places like New York, where the car often stops entirely, says Jose Guerrero, product manager for the BMWi and BMWm. BMW vehicles also will turn the engine back on if it detects that the interior temperature has decreased more than the driver’s preference. The next step is to shut off the engine when the vehicle is decelerating, which could improve fuel-economy by 5 percent to 6 percent, says John German, a senior fellow with the International Council for Clean Transportation.

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Another technology helping gas engines is turbocharging, in which more air is forced into the engine when needed. Turbocharging boosts the power output of an engine, which means an engine can be downsized from a heavier V8 or V6 to a lightweight V4 without sacrificing performance. "It's a no-compromise solution to give you the performance characteristics you're seeking," said Stoller. He said turbocharging can result in fuel-economy gains of 20 percent for a downsized turbo gasoline engine, and 40 percent for replacing a gas engine with a downsized turbo diesel engine.

Turbocharging is used in 23 percent of vehicles in North America today, according to Stoller. Honeywell predicts that share will reach 39 percent by 2020. Used primarily by European car makers at first, turbocharging is now found in nearly every vehicle in Ford’s lineup, Stoller said. It's also more cost-effective than stop-start, since it achieves greater fuel-efficiency gains, he says.

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Automakers are also using lightweight materials to improve fuel economy. Last year, Ford shed 700 pounds from its F-150 truck by using aluminum instead of steel. General Motors’ most recent design of the Chevy Cruze reduced its wight by 200 pounds. BMW’s 7 series is also nearly 200 pounds lighter due to its new “Carbon Core,” a mix of carbon fiber, steel and aluminum, in the car’s interior. 

Computer simulations that allow automakers to optimize the material, shape and thickness for every part of the vehicle "will open the floodgates to lightweight materials and secondary lightweight reduction," German said. Previously, carmakers had to build every part and test it. Now they can predict how those designs will behave before ever building the car.

"Everybody has underestimated what the rate of technology development is these days and therefore the [2025 fuel efficiency] standards will be easier and cheaper to meet than people think," German said.

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But these technologies will still cost consumers, possibly resulting in an increase of $6,000 a car, says Jay Baron, president and CEO of the Center for Automotive Research. He predicts that costly electrification will be necessary, and noted that lightweight materials like carbon fiber are far more expensive than heavier materials. Baron says steel costs 35 cents a pound, while carbon fiber runs nearly $10 a pound. As a result, he says, using carbon fiber over steel only makes financial sense in luxury cars.

But GM’s Nicholson says existing powertrains could make significant inroads in meeting fuel-economy standards, while still giving customers what they want: "We're altering conventional powertrains in unconventional ways not possible 10 years ago.”