Ford’s new twin-turbo gasoline direct-injection EcoBoost engines pack plenty of punch for their size. The 2010 Ford Flex with the 3.5-liter EcoBoost V-6 is rated at 355 hp and 350 pounds-feet of torque. That’s an increase of 35% horsepower and 41% more torque than the Flex’s standard 3.5-liter V-6, while returning the same 16/22 mpg city/highway gas mileage (all-wheel drive model). It's also available in the new Ford Taurus SHO, Lincoln MKS sedan and upcoming MKT crossover.
Brett Hinds, Ford’s advance engine design and development manager, said it will only get better from here.
“The [Flex’s] EcoBoost [engine] is the foundation for us,” Hinds said. “It’s a six-cylinder engine that performs like an eight-cylinder, but we’re looking at many ways to make EcoBoost even more efficient so it can meet future fuel economy and CO2 standards.”
Here are three improvements to EcoBoost that Hinds said Ford is studying:
- Ethanol compatibility: Today’s EcoBoost engines can’t use E85, which has several properties that make it better to use in an EcoBoost engine than in a conventional non-turbo engine. Ethanol has a higher octane and heat-of-vaporization point than gasoline, meaning it combusts at a higher temperature and with greater force (higher compression) than gasoline, while also having a greater capacity to cool the fuel/air mix in the cylinder before combustion. This allows a larger charge to be drawn into the cylinder before ignition.
What it means: An EcoBoost engine running on E85 could produce the same power as the Flex’s 3.5-liter V-6 but with even smaller displacement. This could also improve E85 fuel economy, which is typically less on a per-gallon basis than a gallon of gasoline because of E85's lower energy content.
- Start-stop: Without changing the engine, EcoBoost could share start-stop technology originally developed for hybrid vehicles. Start-stop would automatically shut the engine down when the vehicle is stopped, running accessories like the radio and air conditioning off an upgraded starter motor and bigger battery. Hit the gas pedal, and the EcoBoost engine would fire right back up.
What it means: Idling burns fuel and emits CO2 without helping you reach your destination. Start-stop would reduce both.
- Homogeneous charge compression ignition: The only thing larger than HCCI’s spelled-out name is the technical challenge of making it work in a gas engine. HCCI enables a normally spark-ignited gasoline engine to operate similar to a compression-ignited diesel engine, but only in certain driving conditions.
What it means: Shifting on the fly from spark to compression ignition could yield another 10% to 15% improvement in fuel economy.