This evening GM has unveiled a 2.4-liter direct injection EcoTec four-cylinder that will kick out 180 horsepower while returning a projected EPA highway rating of 30 mpg (Ford's 2.5L I-4 produces 170 hp and returns a maximum of 28 mpg highway). It's a marvelous way to send the old 3.4 liter V6 into the sunset, but if you absolutely must have a V6, there's also a DI 3.0-liter version of GM's excellent "high feature" V6 delivering an impressive 255 horsepower (Again, Ford's heavily revised 3.0L V6 produces 240 hp).
Both engines have been developed with an eye (or ear) toward reducing the typically increased noise of DI engines. There are rubber isolators to keep the fuel rail racket down and attention to noise attenuation was an important aspect of the program. Variable valve timing also allows both engines to be more efficient over a broader rpm range. Backing both powerplants is a six-speed automatic transmission. Now all the General has to do is hang on 'till these cars hit showrooms and pray for higher fuel prices to further drive demand.
GENERAL MOTORS' NEWEST ENGINES HELP SAVE FUEL AND MONEY
- New technologies and vehicle enhancements will enable GM's 2009 domestic car and light truck lineups to save 700 million gallons of fuel over vehicle life as compared to the 2008 GM fleet
- Chevy Equinox four-cylinder model to offer class-leading highway fuel economy
PONTIAC, Mich. – Owners of the 2010 Chevrolet Equinox crossover will hit the streets next summer in a vehicle equipped with a highly efficient, all-new engine that will help save both fuel and money.
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.
GM's fuel-saving lineup
GM's direct injection push is part of a larger effort to implement multiple fuel-saving technologies across its 2009 portfolio. The all-new 2009 Chevy Traverse crossover, for example, enjoys best-in-class highway fuel economy (24 mpg for FWD models) of any eight-passenger SUV, thanks in part to its 3.6L direct injected V-6 engine with variable valve timing. In 2009, GM expects to sell 500,000 vehicles with gasoline direct injection.
Here are additional fuel-saving facts about GM vehicles:
- Twenty models in GM's 2009 lineup deliver EPA-rated highway fuel economy of 30 mpg or more – more than any other automaker. GM's non-hybrid models rank first in highway fuel economy in both the midsize sedan and subcompact segments. (Chevrolet Malibu, Saturn Aura with 33 highway mpg; and Chevrolet Colbalt XFE and Pontiac G5 XFE at 37 highway mpg.)
- GM's 2009 domestic car and light truck lineups will use 700 million fewer gallons of fuel than the 2008 lineup, during the life of the vehicles, saving $1.4 to $2.1 billion in fuel costs, assuming gas prices of $2 to $3 per gallon. It's estimated that GM's 2010 lineup will add another 1.1 billion gallons of fuel savings and $2.2 to $3.3 billion, relative to the 2008 lineup.
GM's advanced engine technologies are already saving fuel today in vehicles on the road or expected to be sold in 2009. They include:
- More than 3.7 million vehicles with variable valve timing (VVT)
- 700,000 vehicles with direct injection
- 600,000 vehicles with Active Fuel Management cylinder deactivation technology, which automatically lets the engine run on half of its cylinders when full power is not needed
- 200,000 vehicles with turbocharged gas engines
- 42,000 vehicles with both direct injection and turbocharging
- More than 2 million vehicles with fuel-saving six-speed transmissions
2.4L 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 and lower 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.