Why six cylinders might be an endangered species

By Edward A. Sanchez | January 19, 2011
It was only a few years ago, when gasoline was hovering around the $4 a gallon level, that many were prognosticating the end of the V8 engine. It was a gratuitous anachronism from bygone days, and destined for the scrap heap of automotive history, the critics claimed. Well, everything needs to be taken in context. 100-150 years from now, the only internal-combustion engines around will probably be in museums and historical parades. But over the next several decades, the internal-combustion engine is here to stay, in some form or another. The question then becomes, what form will it take? It's pretty apparent there's a worldwide trend toward downsizing engines, even among luxury cars, although in that segment, the change is not as dramatic. We're still talking about twin-turbocharged V8s, an indulgent engine configuration by most peoples' standards. Based on trend observations, I think the big loser in the engine downsizing battle may be the six-cylinder. The staunch bread-and-butter standard for decades, the six was a step up from the lowly, rough, pokey four-cylinder economy cars and loss-leader midsize strippers, but more sensible than the thirsty, rumbling V8s at the top of the totem pole.
But we're starting to see the proliferation of increasingly powerful and refined four-cylinders. Some are even supplanting six-cylinders in their respective applications. The first and most notable to come to mind is in Hyundai's midsize Sonata sedan. You can't get a V6 of any size or type in the Korean midsizer. A turbocharged four cranks out as much power as competitors' V6s, but with better fuel economy. Although perhaps not as silky smooth as the best sixes on the market, the new fours are far more polished than their coarse forbears, to the point where many consumers can barely tell the difference from behind the wheel. Among luxury marques, forced-induction four cylinders are starting to make an appearance. Mercedes-Benz, after pursuing an on-again, off-again flirtation with blown fours in its C-class and SLK roadsters in the U.S. market, seems firmly committed to it with its new 1.8 liter direct-injection turbo. With 201 horsepower and a solid 229 lb./ft. of torque. This power output is roughly on par with its 3.0L V6. Even BMW, long the standard-bearer of six-cylinder refinement and performance, looks like it may be replacing its normally-aspirated 3.0 engine with a turbocharged four, leaving the turbocharged 3.0 for higher-performance, higher-trim models in its lineup. Some are hinting that the next-generation Chevy Malibu will be four-cylinder only. It's not hard to make that stretch, as Buick, the one-time standard-bearer for V6 engines at GM, with its once highly-regarded 3800 V6, now has two model lines that are exclusively four-cylinder (Regal and Verano) and even its large LaCrosse model has an available four. Lest you think the crossover and SUV market is immune from this trend, think again. Ford is aggressively touting its EcoBoost engines, in both four and six-cylinder guise, for its midsize crossovers and SUVs. Will there still be six-cylinders around for the next few decades? Certainly. But it looks like the role of the six will change from being the middle-of-the-road engine choice to being the premium, performance option, predominantly turbocharged, either supplanting a normally-aspirated V8, or complementing it. Unlike the V8, which has a particularly passionate and vociferous enthusiast following in the U.S., I think the long, slow fade of the six will be rather quiet and subdued, the notable exceptions being BMW and Porsche enthusiasts, who feel as strongly about their sixes as musclecar devotees feel about their V8s. Most midsize sedan and crossover buyers, want a pleasant driving experience, and good fuel economy. Turbocharged fours deliver on both fronts, further hastening the decline of the mainstream, normally-apsirated six-cylinder. Get ready for the era of turbo fours being the mainstream, midsize engine configuration. The dawn is already upon us.