General Motors Co.: 2.4L DOHC I-4

Special Report

Ward’s 10 Best Engines

It took Ward’s editors 16 years to find a naturally aspirated 4-cyl. in an affordable family vehicle worthy of honoring with a 10 Best Engines award.

We found it this year under the hood of an unlikely vehicle: the ’10 Chevrolet Equinox. The previous-generation model wasn’t bad, but its base engine was an old, overhead-valve 3.4L V-6 rated at 185 hp that delivered middling performance and fuel economy.

The new Equinox, with its spectacular 182-hp 2.4L DOHC direct-injection 4-cyl., leaves its predecessor looking like a dusty relic, sort of like the abandoned assets of the former General Motors Corp., now known as Motors Liquidation Co.

This latest version of GM’s Ecotec I-4 is thoroughly modern, with a cam-driven high-pressure fuel pump and continuously variable valve timing, as well as a precision sand-cast engine block and pistons with jet-spray cooling.

We award extra points to engines that serve many purposes and cross multiple vehicle applications. This transverse-mounted 2.4L Ecotec certainly qualifies, seeing duty in the GMC Terrain and, soon, both the Buick LaCrosse and Regal.

For generations, Buick buyers have expected at least V-6 power, but GM’s confidence in this potent I-4 is well placed.

In the Equinox, this engine never fails to delight with ready throttle response and strong mid-range acceleration. It even enjoys the occasional dash to the redline, moving this 5-passenger ute with surprising vigor. The specific output of 76 hp/L is more than respectable.

There are lots of mainstream similar-sized 4-cyl. engines in the market powering Honda CR-Vs, Toyota Camrys and Ford Escapes, but none of them makes as much power (or the same positive impression) as GM’s 2.4L Ecotec in the Equinox.

What sets the Equinox apart is direct injection, which enables a higher compression ratio in the combustion chamber, which boosts performance and efficiency and helps reduce cold-start emissions about 25%. The driver also can push the “eco” mode button, which alters shift points in the 6-speed automatic transmission to improve mileage.

Several Ward’s editors were astonished to achieve 30 mpg (7.8 L/100 km) in the Equinox in mixed driving, without babying it. The Ecotec 2.4L was a consensus pick for every editor on this year’s judging panel.

The world is taking notice: Dealers are struggling to keep the 4-cyl. Equinox in stock, and waiting lists for the vehicle are growing. It also is a finalist for North American Truck of the Year.

GM has identified direct injection as the powertrain strategy that will drive its recovery in the North American market, one that allows smaller engines to do the work of bigger engines.

Cadillac led the way for GM into the era of DI several years ago with the 3.6L High-Feature V-6 (a 10 Best Engines winner in 2008 and 2009) in the CTS.

Now, this powerful 4-cyl. takes the baton even farther, at much higher volumes. For an affordable, bread-and-butter I-4, the 2.4L Ecotec is as good as it gets.

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Ward's 10 Best Engines is a copyright of Penton Media Inc. Commercial references to the program and/or awards are prohibited without prior permission of Ward's Automotive Group.