For 2010, the biggest change to the Flex, Ford's retro-classically styled people mover, is the option of a turbocharged V-6.
Ford's shrewdly named—and relentlessly promoted—Ecoboost engine displaces the same 3.5 liters as the standard V-6 but it makes a whopping 355 hp (vs. 262) and 350 pound-feet of torque (vs. 248). And all that extra output comes with no fuel economy penalty. With either engine, the all-wheel-drive Flex is rated at 16/22 mpg.
The turbo V-6 is only available with all-wheel drive, since sending 350 pound-feet of torque to the front wheels would be a recipe for hellacious torque steer. Included with the turbocharged engine are shift paddles (rather silly on a big family wagon), 20-inch wheels, and electric power steering. The latter means that the Ecoboosted Flex can be had with Ford's surprisingly effective automatic parking assist option (for $550).
The more powerful engine is certainly effective at moving the hefty Flex, and the fact that is uses no more fuel than the standard V-6 would seem to make it a no-brainer. But in fact, I feel the same way about the Ecoboost engine as I do about the Flex overall: I really like it, but I wish it weren't so damned expensive.
The Ecoboost engine is not available on the SE, only the SEL and the Limited. The Ecoboost price premium over the AWD Limited is $3790; on the AWD SEL (where it's bundled with a $2500 convenience package and leather seats), the turbo engine adds a whopping $6890 to the bottom line. All of which means that you can't get a Flex with Ecoboost for less than $40,000.
As much as I admire an engine that makes 28 percent more power but doesn't use any more fuel, when it comes to the Flex, what I really admire is the truly usable 7-seat packaging; the plentiful cargo space; and the low-slung, anti-SUV styling. So I would likely leave the Ecoboost box unchecked, in an attempt to end up with a sticker price that starts with the somewhat more reasonable number, "3".