Powerful and Fuel Efficient
What do you think of when you hear V8 engine? Tough. Powerful. Strong. But probably not fuel efficient. And yet... here we are with a Best V8 Fuel Efficiency of any Full-Size Pickup* title for the Sierra 5.3L V8 with six-speed transmission.
What's even more impressive is that Sierra doesn't sacrifice any power to hold this title. In fact, Sierra's 5.3L V8 VVT engine generates 326 horsepower and 348 lb.-ft. of torque. That's an increase of 11 horsepower and 13 lb.-ft. of torque for 2011.
There are essentially four features that when combined give Sierra the advantage. They are Active Fuel Management ®, Variable Valve Timing (VVT), a six-speed automatic transmission with two overdrive gears and a numerically lower 3.08 rear axle ratio.
Active Fuel Management
Active Fuel Management increases fuel efficiency by shutting down four cylinders under low power-demand operating conditions, such as when cruising at highway speeds or on level stretches of road. When power demands increase, such as driving uphill, the engine switches back to eight-cylinder operation. Cylinder deactivation and reactivation are executed with seamless precision so the driver will never feel a thing.
Variable Valve Timing (VVT)
Variable Valve Timing or VVT as it's often referred, is a type of engine technology that alters the timing of the valve opening and closing in order to optimize the combustion cycle efficiency. The benefit of this is more power, improved gas mileage and flexibility for an engine to deliver peak performance over a variety of driving conditions. A VVT engine essentially maximizes fuel to the last drop.
Transmission & Rear Axle Ratio
The last piece of the puzzle is Sierra's 5.3L V8's standard six-speed automatic transmission with two overdrive gears. This transmission uses a taller 3.08 rear axle ratio (3.08:1) in order to reduce engine revs relative to road speed, thereby burning less fuel and improving fuel efficiency at highway speeds.
When you're talking about big trucks that need to tackle tough jobs, fuel efficiency may not be the highest priority. Still, it's nice to know that GMC has thought about it for you.
* Based on Wardsauto.com Large Pickup Segment. 2011 GMC Sierra 4x4, with the Vortec 5.3L engine and 6 speed transmission, and competitive fuel consumption ratings based on Natural Resources Canada's 20110 Fuel Consumption Guide. Your actual fuel consumption may vary. Excludes hybrids and other GM models.
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