Opportunities in Engine Downsizing for Light Vehicles
Just because governments around the world are pushing for lower emissions and increased mileage from vehicles doesn’t mean consumers are ready for smaller cars with less powerful engines. In fact, just the opposite is happening. Global demand for pickup trucks and SUVs is booming. And OEMs are managing to simultaneously drive down costs, maintain performance levels, and achieve emissions and fuel economy improvements. But how?
As we are seeing at the North American International Auto Show, light-weight materials, more advanced transmissions, and engine downsizing are all playing a role. For example, steel is being replaced by aluminum, plastics, carbon fiber, and a variety of composite materials. And basic transmissions have become incredibly advanced, with continuously variable transmission (CVT) and continuously variable planetary (CVP) technologies offering significant improvements in efficiency. Then there’s the trend toward engine downsizing – the development of smaller engines with fewer cylinders that provide the same power as a larger engine, thanks to a number of technology improvements.
The WardsAuto global powertrain forecast projects that more than half the light vehicles built globally in 2014 will have engines with displacements from 1.0L to 1.9L, compared with 49 percent in 2013. This difference may seem small, but it actually translates to an additional 15 million units for 1.0L to 1.9L engines by 2020.
Suppliers are capitalizing on this trend by developing innovative ways to provide power to a vehicle’s wheels more efficiently. Turbocharging has become very common, and many of the vehicles introduced at this year’s North American International Auto Show feature turbocharged engines, including the 2014 Cadillac CTS, the Mazda3, and the Jeep Cherokee, all of which were nominees for the 2014 North American Car of the Year Award.
Suppliers are also finding innovative ways to improve transmission efficiency through CVT technology. At Dana, we’re taking this to the next level with our VariGlide™ technology, a unique CVP device. The CVP is a type of continuously variable transmission that uses planets and is analogous to a planetary gear set. This next-generation transmission is capable of seamless shifting through an infinite number of forward speeds, changing the way mechanical power is transmitted and reducing transmission complexity, while allowing the engine to operate at maximum efficiency. For light vehicles, this technology can increase fuel efficiency by 10 percent or more while also improving driveability and powertrain smoothness.
Powertrains that are being pushed harder than ever also produce more heat. Currently, up to 65 percent of the heat energy produced in internal combustion engines is wasted. Typically, the powertrain dissipates the heat by convection, where it is carried to the cooling circuit or lost through the tailpipe as exhaust. Fortunately, this engine heat can be both managed with a variety of thermal technologies, and captured for reuse. Products like Dana’s thermal-acoustical protective shielding (TAPS) protect from extreme temperatures, suppress noise, and lower overall mass with the use of thinner materials, leading to increased fuel economy. Heat exchanger technology, including active-warm-up, captures otherwise wasted engine energy to improve fuel economy and cold start emissions. The key for these thermal management technologies is that they are scalable based on engine size, and can be applied to a variety of platforms, enhancing design flexibility for OEMs.
These are challenging but exciting times. Suppliers have the opportunity to rethink heating and cooling options, and even exhaust heat capture. We also have the opportunity to create the next generation of transmissions and powertrain systems for the global vehicle market.
- What else can be done with the excessive heat these smaller engines are producing?
- What other technologies can help OEMs successfully downsize engines while maintaining power and performance?
Published by David Nash