2010 Ford Flex

Ford Flex turns heads with its distinctive design – and in 2009, the unique full-size crossover becomes even more noteworthy, thanks to an available twin-turbocharged 3.5-liter EcoBoost V-6 engine.

This all-new engine gives Flex V-8 power and performance feel with the fuel economy of a V-6.

The twin-turbocharged 3.5-liter EcoBoost V-6 produces an estimated 355 horsepower at 5,700 rpm and 350 foot-pounds of torque at 3,500 rpm. In addition to the power upgrade, the 2010 EcoBoost Flex boasts segment-leading fuel economy among full-size performance crossover vehicles with 22 mpg highway and 18 mpg combined.

The 2010 Flex has unsurpassed fuel economy in the full-size crossover segment with 24 mpg highway and 19 mpg combined, one of a number of new Ford products delivering the best or among the best fuel economy.

The twin-turbocharged 3.5-liter EcoBoost V-6 engine requires all-wheel drive and will be available on well-equipped SEL and Limited models of the 2010 Flex, packaged with several high-demand customer features.

The EcoBoost program is part of Ford’s ongoing and wide-ranging initiative to deliver fuel-efficient powertrain systems with power and performance found in larger-displacement engines.

“EcoBoost engines offer more power and better fuel economy,” said Brett Hinds, EcoBoost design manager. “It’s all part of Ford’s strategy to bring adaptable powertrain technology to all kinds of vehicles and all kinds of lifestyles. This technology is affordable and applicable to all gasoline engines.”

Hinds said the 3.5-liter EcoBoost V-6 will handle any tasks Ford Flex drivers ask of it. “The drivability of EcoBoost engines is superior and it just generates a lot more confidence in your Flex – it goes where you want it to go,” he said. “You’re rewarding yourself as a driver.”

The twin-turbocharged 3.5-liter EcoBoost V-6 also will arrive in the Lincoln MKS and MKT in 2009. Although these are three very different vehicles that serve different needs for customers, the EcoBoost engine can handle the roles seamlessly and effectively. The 2010 EcoBoost V-6 MKT, for example, provides segment-leading fuel economy, exceeding the V-8-powered Audi Q7 by 4 mpg on the highway.

The key to the EcoBoost system is the harmony between the twin turbochargers and the direct injection fuel system. The turbochargers recover energy from the exhaust that otherwise would’ve been wasted and put it back in the engine to gain efficiency. Simply, the turbocharging system puts more air into the engine for more power. A compressor increases or “boosts” the pressure of the air entering the engine. An intercooler reduces the air temperature before it enters the engine.

The twin parallel turbochargers, which are water cooled and operate simultaneously, combine with a direct-injection fuel system to produce power when the driver pushes down on the gas pedal. The high-pressure fuel pump operates up to 2,175 psi – more than 35 times the norm seen in a conventional V-6 engine. The high-pressure pump is a cam-driven mechanical pump with a single piston and an electronic valve that controls how much fuel is routed into the fuel rails to the injectors.

As demands on the twin-turbocharged 3.5-liter EcoBoost V-6 engine are increased, the control system responds to maintain optimal combustion, timing and injection duration.

On each stroke, six individual jets spray fuel directly into the combustion chamber, mixing with the incoming air. “By bringing the fuel injector right into the combustion chamber, there’s no delay from the time you inject the fuel to when it’s used by the engine,” Hinds said.

The fuel injectors are located on the side of the combustion chamber. When the fuel is injected into the cylinder, it evaporates and cools the air that’s been inducted into the cylinder. “Another benefit of our direct injection method is that it cools the air right where you’re going to burn it,” Hinds said. “This action both improves the breathing of the engine and minimizes knocking.”

The direct injection of fuel into the cylinder also helps provide a well-mixed air-fuel charge, increasing engine efficiency. Direct injection provides several benefits in terms of fuel burn and lower emissions.

The spray pattern for the fuel was optimized after extensive modeling work, with the angle of how the fuel is sprayed key to the process.