GM 2.0L Turbocharged I-4

Cadillac’s first 4-cyl. engine in decades had to be good, and the all-new turbocharged 2.0L does not disappoint.        

General Motors recently has received accolades for its work on the alternative powertrain in the Chevy Volt and its legendary small-block V-8, but it has not been given its due for developing small, power-dense engines.

In 2007, GM’s 260-hp 2.0L Ecotec-branded engine was the first North American engine to feature gasoline direct injection. It was a bit rough around the edges, but with 260 lb.-ft (353 Nm) of torque, it packed quite a wallop for a mainstream 4-cyl. engine and laid important groundwork for the future.

GM really turned our heads last year with the highly refined 2.0L in the Regal GS making 270 hp and a whopping 295-lb. ft. (400 Nm) of torque. With 135 hp/L, it literally made it into the record books as the highest specific-output engine ever certified by the Society of Automotive Engineers.

This year, GM follows up with a completely new turbocharged 2.0L for the Cadillac ATS making 272 hp and 260 lb.-ft. Except for a few fasteners, everything is new. Even the intake and exhaust systems are on opposite sides.

Yes, the new engine has 35 lb.-ft. (47 Nm) less torque than its predecessor, but it actually does a better all-around job of transferring its abundant power to the pavement. Instead of having a tall crest, the torque curve now is broader, delivering 90% of peak twist at just 1,700 rpm.

Coupled with the immediate throttle response offered up by the twin-scroll turbo, the flatter torque curve provides more consistent and predictable thrust to the rear wheels. This complements the perfectly balanced driving dynamics of the ATS, whether trying to execute a perfect corner exit on the track or just puttering through commuter traffic.

Thanks to major reductions in friction and technologies, such as a variable-displacement oil pump, efficiency also has been improved.

One editor managed 26.9 mpg (8.7 L/100 km) on a weekend trip. The rest of us averaged about 23 mpg (10.2 L/100 km) in mixed city/highway driving.

Ultimately, the new 2.0L provides all the benefits of a much larger V-6 without the negatives of more weight and poorer fuel economy. This is an unsung hero that really sings.

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