With the 2010 model year, Ford is marking the start of its EcoBoost initiative, a plan that will dramatically effect the company's entire lineup in the coming years. By using turbocharging and direct injection with smaller-displacement engines, Ford says it can offer better performance and fuel economy. The company expects it will put 1.3 million EcoBoost engines on the road by 2013 and offer the technology in 90 percent of its models.
The Flex crossover is one of the first Fords to get EcoBoost. Using a 3.5-liter V-6, the Flex achieves V-8 performance with V-6 fuel economy. The Flex EcoBoost (which is only available with all-wheel drive) achieves the same fuel economy as the base all-wheel-drive Flex, which is rated at 16/22 mpg.
Powertrain
The technology in Ford's EcoBoost engines isn't revolutionary, but the company's plan for such widespread adoption is unique. In the 3.5-liter V-6, two turbochargers spin as fast as 170,000 rpm to force more air into the engine while fuel injectors spray gasoline into the cylinders at 2175 psi. Adding more air and fuel allows extra power to be squeezed out of each combustion event.
There are plenty of automakers that might detune a performance engine by 10 to 20 hp in the family crossover, but the Flex receives the same 355 hp that will move the Ford Taurus SHO, the Lincoln MKS, and the Lincoln MKT. Ford has decided that its first EcoBoost engine needs to place more emphasis on performance than fuel economy in order to build a positive impression of the technology. Future Ford engines using turbochargers and direct injection may focus more on the fuel economy side of the equation. Torque is rated at 350 lb-ft and spans from 1500 to 5250 rpm. It's that plateau-flat torque curve that creates an exciting and effective blast when the throttle is planted. Ford estimates 0-to-60-mph acceleration occurs in about 7 seconds.
EcoBoost Flexes all receive a manual-shift mode for the six-speed automatic transmission, along with steering-wheel-mounted shift paddles. The paddles are a great addition for the performance engine but could use some refinement. When the gear selector is left in drive, the paddles can't be used to effect a downshift. In manual mode, the transmission is happy to provide downshifts at a fairly quick pace but sometimes isn't restrictive enough (yes, we just said that). Multiple times, we asked for one too many downshifts, and the Flex obliged by dropping down a gear - right on top of redline. To top it off, the coarse, dull finish on the plastic paddle shifters looks out of place compared with the rest of the well-trimmed cabin.
More than an engine upgrade
The Flex with EcoBoost is more than just a Flex with a different engine. The engineering team has also modified the suspension with stiffer springs, higher damping rates, and a ride height that has been lowered by ten millimeters. Combined with the already-low ride height and excellent body control, the subtle changes make this Flex one of the best handling crossovers on the market and do a good job of disguising its 4839-pound weight.
Ford has also equipped EcoBoost Flexes with electric power steering (the base Flex will continue to use a hydraulic system). The primary advantage is that Ford can now incorporate its Active Park Assist (see below), but the system also adds a feature called Pull-Drift Compensation. When a driver has the steering wheel slightly turned to keep the vehicle straight on a crowned road or in strong crosswinds, the computer recognizes it and activates drift compensation. By adding small amounts of torque to keep the wheel off-center, the driver can reduce the amount of effort to keep the wheel cocked and car straight.
The enthusiast's crossover
Ford touts EcoBoost's advantages with a pragmatic slant: better towing with above-average fuel economy. We agree that those are admirable attributes. But driving the winding roads of the Rockies outside of Boulder, Colorado, we came to admire the Flex EcoBoost as something else: an enthusiast's crossover. Combined with confident body control and surprising handling, the torque-monster engine creates a fun driving experience. All-wheel drive provides sure footing, and the paddle shifters allowed us to run up and down through the gears and keep boost at the ready.
To emphasize the Flex's towing credentials, Ford took us to Estes Park, Colorado, at an elevation of approximately 7500 feet. Towing trailers that were loaded with 2500 pounds of ATVs and dirt bikes, we ran up mountain roads in a GMC Acadia, a Dodge Durango Hemi, and a Ford Flex EcoBoost. While the normally aspirated engines--a 3.6-liter V-6 in the Acadia and a 5.7-liter V-8 in the Dodge Durango--wheezed from a lack of air, the Ecoboost's turbochargers kept the Flex steaming ahead. At sea level, the Hemi and the EcoBoost are on a much more level playing field - but the earth is not flat. The Flex can pull up to 4500 pounds and comes standard with a trailer sway control system when equipped with the towing package. ...next page >>