Chevy Equinox four-cylinder model to offer highly efficient, all-new engine

2010 Chevrolet Equinox

The 2010 Equinox will be offered with a choice of two new direct injected (DI) engines that use less fuel yet make more power – a 2.4L four-cylinder and a 3.0L V-6. The 2.4L engine delivers an estimated 30 mpg in highway driving (EPA certification pending), placing the Equinox at the top of its segment in highway mileage. Consumers who drive the 2.4L-equipped Equinox 15,000 miles per year will save 134 gallons of fuel or about $270 to $400 annually (assuming gas prices of $2 or $3 per gallon as compared to 2009MY Equinox).

The Equinox will join a growing roster of direct injected vehicles from GM, including the all-new 2010 Cadillac SRX crossover and 2010 Buick LaCrosse sedan, which, along with the Equinox, debut in January at the North American International Auto Show in Detroit. In fact, for the 2010 model year, GM will offer more DI models in North America than any other manufacturer.

“We first introduced direct injection in North America in the 2007 Saturn Sky Red Line and the Pontiac Solstice GXP,” said Tom Stephens, executive vice president, GM Global Powertrain and Global Quality. “We’ve been rolling out the technology across our portfolio as quickly as we can so that our customers will have additional fuel savings options. Direct injection is a state-of-the art engineering solution because it enables improved fuel economy and lower emissions without sacrificing power.”

In the 2009 model year, GM offers six engines in 18 models globally with direct injection. By 2010, GM will have eight direct injected engines in 38 vehicle models, covering 10 percent of its global volume. In North America alone, GM will offer 18 models with direct injection.

.4L DI details

The new 2.4L DI engine delivers an estimated 180 horsepower (134 kW) @ 6700 rpm and 172 lb.-ft. of torque (232 Nm) @4900 rpm. It uses technology based on GM’s other four-cylinder direct injection applications, but with unique features designed for its specific application. This includes an 11.4:1 compression ratio that helps build power, slightly dished pistons that increase combustion efficiency and injectors with an application-specific flow rate.

GM benchmarked the best fuel system and noise attenuation products to provide customers with quiet operation.

3.0L DI details

The new 3.0L DI engine is a variant of GM’s family of high-feature DOHC V-6 engines that also includes GM’s 3.6L DI engine in the Cadillac CTS – an engine named to Ward’s AutoWorld’s 2009 “Ten Best Engines” list for North America, for the second consecutive year.

The 3.0L is rated at an estimated 255 horsepower (187 kW) and 214 lb.-ft. of torque (290 Nm), for an impressive power-to-displacement ratio of 85 hp per liter. (Output will vary by model.) The 3.0L DI features an isolated fuel injector system that reduces the direct injection high-pressure fuel system pulses for quieter operation. Rubber isolators are used with the fuel rail to eliminate metal-to-metal contact that would otherwise transmit noise and vibration from the high-pressure fuel system.

Along with direct injection technology, both the 3.0L DI and 2.4L DI engines use variable valve timing to optimize power and fuel efficiency across the rpm band, as well as reduce emissions.

How DI works

In a conventionally port fuel injected engine, air and fuel are mixed before they enter the combustion chamber. With GM’s DI engines, fuel is sprayed directly into the cylinder where it is mixed with air. As the piston approaches top-dead center, the mixture is ignited by the spark plug; and when the fuel vaporizes in the cylinder, the air and fuel mixture is cooled. This enables the use of a higher compression ratio in the combustion chamber, which improves the engine’s power and efficiency.

On cold starts, direct injection can be controlled to create a richer air/fuel mixture around the spark plug, making it easier to ignite in a cold engine. This results in a smoother operation of the engine andlower emissions during the cold start and warm-up, when most harmful tailpipe emissions are typically created. GM’s direct injected engines reduce cold-start vehicle emissions by 25 percent.

Because the fuel is injected directly into the combustion chamber, direct injection uses higher fuel pressure than conventional fuel injected engines. This is enabled by a special high pressure pump driven by one of the engine’s camshafts.

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