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The 2011 Buick Regal offers buyers a choice of a 182- horsepower four- cylinder or a 220-horse turbo 4 engine. (GM Media)
As automotive earth saviors go, electric cars and hybrids are widely presumed to be the chosen ones.
But as carmakers and consumers seek real, affordable gains in miles per gallon, it will be the once-humble 4-cylinder combustion engine that takes them there -- far more than electrics or hybrids, which are years away from selling in numbers that would rein in the nation's greenhouse emissions and appetite for oil.
The new allure of 4-cylinder engines certainly defies the odds. From the '70s through the '90s, as Japan rode small cars to world-changing success, Detroit's compacts were poor ambassadors for the 4-cylinder. American economy cars like the Chevrolet Vega and Ford Escort limped along with base-level 4s that were often rackety, unreliable and weak-kneed. When trucks, particularly SUVs, became King of the Hill in the new millennium, buyers reflexively chose a V-6 or a V-8.
Today, though, American buyers shifting to smaller cars and lighter crossovers are discovering downsized engines strong enough to meet their needs. This year, 47 percent of new vehicles have four cylinders under the hood, according to J.D. Power & Associates, a remarkable jump from 30 percent in 2005. Over that time, the market share of V-8s has fallen to 16 percent, from 26 percent.
As for family sedans, more consumers are skipping the optional six cylinders for fuel-efficient 4s. Through July, 93 percent of Nissan Altima buyers chose the 4-cylinder version, up from 85 percent in 2007, just before fuel prices soared and the car market tanked. The 4-cylinder Ford Fusion, which attracted 55 percent of buyers in 2007, now accounts for more than 70 percent of sales.
Those buyers are finding engines much more refined than the 4s of their parents' generation -- still stingy on gas, but surprisingly smooth and powerful. So much so that the modern engines, girded with power-aiding technologies like turbochargers and direct injection, can beat many V-6s in both horsepower and fuel economy.
Civilizing the 4-cylinder engine, a popular power source for American vehicles dating to the Model T, once posed a huge challenge. While in-line 4s can be elegantly simple, the up-and-down motion of their pistons produces an annoying imbalance that grows with engine size.
Modern 4-cylinders provide relief from the buzzing by using technologies that can quell the inherent noise and harshness, including counterbalance shafts, sophisticated combustion controls and improved sound deadening and engine mounts.
General Motors' Buick division offers a choice of two 4-cylinders with its 2011 Regal. A version of the stylish Opel Insignia sold in Europe -- where even big autobahn cruisers rely on smaller gas or diesel engines -- the midsize Regal is available with a 182-horsepower 4-cylinder or a 220-horse turbo 4.
Let's not overlook the green elephant in the room; this trend is not driven entirely by consumer demand or environmental consciousness on the part of automakers. Around the world, downsized engines are the linchpin of strategies to meet stricter fuel-economy and pollution rules, including limits on carbon-dioxide emissions.
Even at companies like Ford, which has ambitious plans for electric vehicles, leaders say that downsizing engines in mainstream products will save vastly more fuel than will hybrids, diesels or electrics -- and at much lower cost to consumers.
Ford has pledged to put 1.3 million of its EcoBoost engines on the road by 2013 -- two-thirds of them 4-cylinder versions -- and to offer them in 80 percent of its model lineup. Brett Hinds, Ford's manager of advanced engine design, called EcoBoost "the cornerstone of our sustainability efforts."
"A hybrid can have a big impact per vehicle, but the numbers sold are relatively small," Hinds said. "EcoBoost engines can have a large-scale impact on global carbon dioxide, fuel consumption and oil imports."
DN Auto Insider
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