2011 Buick Regal – 2.0-litre turbocharged engine. Click image to enlarge
Manufacturer’s web site
By Frank Rizzuti
2011 Buick Regal
In its simplest form, a turbocharger is a small centrifugal pump which is driven by the energy of the exhaust gases of an engine. This is used for forced induction, which increases the air pressure entering the engine to increase power. The main goal of a turbocharger is to improve an engine’s volumetric efficiency, which is the ratio (or percentage) of what quantity of fuel and air actually enters the cylinder.
On a naturally aspirated engine, the downward stroke of the piston is what’s used to create the area of low pressure to draw air into the cylinder. On a turbocharged engine the turbo creates a greater mass of air, making it possible to create a bigger explosion when more fuel is injected – thus increasing power and torque.
Invented by Swiss engineer Alfred Büchi in 1905, the first turbochargers were used in diesel ships and locomotives in the 1920’s. Some of the first turbos used in the automotive world were in the 1962 Oldsmobile Cutlass Jetfire, 1962 Chevrolet Corvair Monza Spyder and the 1972 Buick Regal, among others. Fast forward to the present and the turbo once again reappears in the 2011 Buick Regal.
2011 Buick Regal; bottom photos by Frank Rizzuti. Click image to enlarge
Available in the 2011 Buick Regal CXL, the Ecotec 2.0-litre turbocharged and direct injected four-cylinder engine is rated at 220 horsepower and 260 lb.-ft of torque. Direct-injection alters the point where fuel enters the engine much closer to where it will be ignited; the outcome is a more complete burn, which allows for a leaner mixture. But the best part is that less fuel is required to achieve the same horsepower as a conventional, port-injection fuel system. The result is a very smooth, quiet, efficient and powerful engine,
According to GM, this engine was subjected to one of the toughest most comprehensive testing processes ever, which included millions of miles of real-world testing over an extensive range of climates and environments.
GM engineers designed each and every aspect of the engine while taking into account the extra stresses that a turbo can put on vital engine parts. The Ecotec 2.0-litre Turbo engine block is sand-cast and is superior to previous Ecotec engine block castings. This has resulted in improved structural support with less noise, vibration and engine harshness. The main bearing bulkheads have been strengthened as well as refinements to the oil distribution system that have resulted in improved oil flow. The pistons are lightweight cast aluminum and the tops are dish-shaped to optimize the combustion benefits of direct-injection. The cylinder heads are cast aluminum and have also been specifically designed for direct-injection.
The turbocharger itself is a unique twin-scroll design that is electronically controlled. Each scroll (turbine) is fed by separate exhaust passages, one by cylinders one and four and the other by cylinders two and three. This design virtually eliminates turbo lag and immediate throttle response is achieved. The turbocharger provides a maximum of 20 psi of boost.
All of this technology has resulted in an engine that is quiet and smooth, something Buick owners are expecting, and it’s also relatively fuel efficient. I averaged 12.5 L/100 km of mostly city driving during my week with the Regal. But the performance that the turbo dishes out is a real surprise, and hitting the loud pedal will launch you into the next postal code with authority, something Buick owners aren’t expecting.
The 2011 MSRP of the 2011 Buick Regal Turbo CXL-T (as tested) is $39,645.00.