We’ve dubbed it “the little engine that could” and for good reason. The turbocharged 1.3L 3-cyl. we tested in the ’21 Chevrolet Trailblazer lives up to that description in nearly every way.
Producing 155 hp and 174 lb.-ft. (236 Nm) of torque, the engine elbowed its way onto our 2021 10 Best Engines & Propulsion Systems list through a combination of technology, tidy sizing and torquey response. Putting it over the top is an impressive output of 116 hp per liter – outpacing its much bigger V-8 brethren in the Corvette Stingray by 37 hp per liter.
That’s not to take anything away from the 6.2L OHV small-block in the Stingray, a mid-engine application that made our 2020 list and remains among our favorites when it comes to pure performance. But time moves on, bringing with it a different type of responsiveness in a much, much smaller configuration in the well-equipped $30,730 Trailblazer compact CUV.
The clean-sheet Ecotec I-3 had to balance a list of tough objectives as the architecture is intended for multiple global applications: strong transient response, low NVH and good fuel economy/low CO2 emissions, depending on the vehicle size.
The all-aluminum DOHC engine is fed by a single-scroll turbo hooked to a head-integrated exhaust manifold to assure quick boost pressure, direct fuel injection and intake and exhaust cam phasing. A nearly invisible 12V stop/start system further aids fuel economy, which is listed at 26/30 mpg (9.0-7.8 L/100 km) city/highway for our all-wheel-drive, 9-speed automatic test vehicle.
Active thermal management employs an electric water pump and a control valve that helps specific areas of the engine to warm or cool quickly as needed, while a variable-flow oil pump performs a similar function to reduce friction.
To keep the engine quiet and refined, engineers employ a deep-skirt cylinder block with an integrated balance shaft, stiff engine and transmission mounts, a high-inertia crankshaft dampener and acoustic covers over the engine and fuel pump and fuel rails.
Quietly delivering ample power from only three cylinders impressed our judges.
“This engine works beautifully with this vehicle,” says judge Drew Winter. “Nobody has to know the Trailblazer has only three cylinders.”
“Most people behind the wheel would never know there’s only three cylinders doing the work,” agrees editor Tom Murphy. “The engine seals the deal. It’s fun to discover a great engine in a high-volume, affordable, mainstream vehicle that seats at least four passengers comfortably, with cargo room to spare.”