Chrysler is unveiling a way to squeeze more fuel efficiency out of existing gasoline engines, adopting a technology pioneered by Fiat, which controls Chrysler. The effort represents the latest strategy by automakers to meet federal standards that require an automotive fleet to get an average of 35.5 miles per gallon by 2016.
While General Motors and Ford have made progress in retooling their gasoline engines to make them more fuel-efficient, Chrysler has lagged. Now Chrysler hopes to catch up with the MultiAir technology, which it claims will increase fuel economy by 25 percent.
In a conventional engine, a camshaft opens and closes the valves that bring air into the engine. These valves all make the same movement all the time, even at low engine speeds, when less air is required. The MultiAir system is different because it electronically determines the most efficient way to open and close the valves, depending on road conditions and necessary power, allowing the car to run more efficiently at all speeds.
Here’s how it works: A small solenoid, a mechanical device that can act like a switch, opens and closes the valves. This solenoid adjusts the cycle of valves opening and closing so that the engine takes in the best amount of air for the load it’s handling at any given moment. Opening the valves for a short period of time at low loads is less work for the engine, increasing its efficiency. And because the system can open the valves longer when more power is needed, it can extract more energy out of the engine.
As a result, MultiAir not only increases fuel economy, it also increases the engine’s torque by 15 percent, says Chrysler spokesman Nick Cappa.
“It gives the engine a more efficient breathing pattern whether at idle or 6,000 rpm,” Cappa says.
The MultiAir technology was launched by Fiat in Europe in 2009. Its first application in the U.S. will be on the 2011 Fiat 500. Cappa says Chrysler is looking to use MultiAir on its new, more efficient Pentastar six-cylinder engines, which are used in everything from pickup trucks to small sedans. Cappa says the cost of adding the technology to a car hasn’t been determined yet.
Chrysler’s use of the technology is the latest attempt to improve the fuel efficiency of internal combustion engines. Shifting to radically different engines, like those in electric cars, may offer the best long-term benefits for the environment and fuel economy. But the infrastructure necessary for vehicle charging stations won’t spring up overnight.