Ford Fusion makes noise to keep the car quiet
The 2013 Ford Fusion employs active noise cancellation to help hide the unpleasant noise of a naturally unbalanced four-cylinder engine at some Rev. ranges. One reason that the in-line 6 cylinder and 8 cylinder engine have become so beloved by enthusiasts over the century of motoring is that they are naturally able to offset vibrations made by the rotating camshaft, connecting rods and pistons. As one piston goes up, another someplace else in the engine is going in the opposite direction and that helps to make the engine vibration free, and hence, noise free. Unfortunately, most cars that are designed for fuel efficiency these days, including the vast majority of hybrids, use in-line four cylinder engines. These are not naturally balanced and can be made tolerable with counter-rotating balance shafts. Nevertheless, the engine will sing a sad song at some speeds.
In order to combat the raucous noise made by a four-banger being controlled by a continuously variable transmission (CVT), Ford’s 2013 Fusion has a noise generator that cancels out the bad noises coming from the drivetrain. CVTs have a tendency to thrum and then groan, instead of offering the driver the sounds of a shifting transmission the driving public has become accustomed to. In many vehicles the drivetrain is optimized to bring the owner of the vehicle the overall best experience,. Fuel efficiency is just one parameter considered. When engineers design the transmission they take into account the areas of operation that sound lousy and just program the car’s computer to not operate the engine at those speeds. However, the Fusion is all about fuel efficiency. Therefore, it would be wasteful to avoid operating the vehicle’s engine at some points just because it sounds bad. Henry Ford Technical Fellow for NVH (Noise, Vibration and Harshness) Dr. Takeshi Abe explained it this way in a recent press release “The Fusion Hybrid leverages this advanced technology to help deliver maximum fuel economy for the customer. Reduced powertrain noise in the passenger compartment becomes the icing on the cake.”
Active noise cancellation is not completely new to the auto industry. The Honda Odyssey employed it many years ago to make the cabin as quiet as possible in conjunction with active cylinder management. Fusion’s use is similar, but the idea that a noisy machine can be the best design and made tolerable by sound engineering is a bit of a new concept.
The 2013 Ford Fusion Hybrid employs as many cutting edge technologies as possible to achieve the 47 mpg rating most important to its buyers.