Over the past 10 years automakers have looked closely at many part of the gasoline engine to increase both fuel efficiency and also power. Many times these two go hand in hand. If an automaker can find a way to increase power and save fuel, it can then reduce the size of the engine as well, which in itself leads to more fuel efficiency. Fuel delivery has had a lot of attention lately. Turbochargers compress the intake air using waste energy from the exhaust stream. New, high-tech fuel delivery systems such as direct injection then use precise amounts of fuel to make the most of the liquid gold going into the combustion chamber. One thing that is easy to overlook is that the fuel and air still need to find their way past valves to enter the cylinder and that is where Chevy’s newest innovation comes from.
Variable valve timing like the syetem employed on the 2014 Chevrolet Impala works by simply allowing the engine management system to open and close the valves at different times depending upon the engine load. For example, in one scenario a quick opening of the intake valve may be preferred to a slow opening. In older engines the valves were strictly mechanically operated based on the camshafts rotation and they opened and closed the same way all the time. Chevy’s new system shines a light on how important the intake valves actuation is to the engine’s efficiency.
The new 2014 Chevrolet Impala will incorporate Intake Valve Lift Control (IVLC). By varying the lift (how far away from the cylinder closure the valve backs up), and duration (How long the valve stays open) the engine gets the benefits of both a fuel sipping valve and also a high performance vale only when needed. Mike Anderson, GM global chief engineer for Ecotec engines explained the result in a press release this way; ““Intake Valve Lift Control works so seamlessly drivers aren’t likely to notice it at all. What they will notice is a fuel savings of up to one mile per gallon.” One mpg can be a 5% savings.
Chevy will use direct injection and other fuel savings technologies in all of the new Impala’s engine offerings.