Since Ford launched its line of downsized EcoBoost engines in 2009, the "eco" part of that name has often required an asterisk.

That's because some owners have found that real-world fuel economy results don't always live up to the vehicles' official EPA ratings.

The phrase "you can have Eco, or you can have Boost, but you can't have both at the same time," frequently crops up in reviews and on owner forums.

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But when it comes to the new Ford GT supercar, it seems you can't have "Eco" at all.

Making its public debut two years ago at the 2015 Detroit Auto Show, the GT uses a modified version of Ford's 3.5-liter twin-turbocharged EcoBoost V-6.

The GT is only just now entering production, which means EPA fuel-economy ratings are now available.

2017 Ford GT

2017 Ford GT

They aren't very impressive.

The GT is rated at just 14 mpg combined, meaning the car gets slapped with a gas-guzzler tax of about $3,000 (its purchase price is estimated at around $400,000), notes Car and Driver.

It also means—despite its much smaller-displacement engine—the GT is just as thirsty as virtually every other exotic supercar.

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Ford's EcoBoost-powered effort only bests the Lamborghini Aventador—which has a 6.5-liter V-12 engine—by 1 mpg combined.

A similar version of the 3.5-liter EcoBoost engine is rated at 16 mpg combined in the 2017 Ford F-150 Raptor pickup truck.

That engine is tuned to be less powerful than in the GT, and is mated to a more efficiency-focused 10-speed automatic transmission, but the Raptor is substantially heavier and less aerodynamic than the GT.

Ford GT race car, 2016 Rolex 24 At Daytona

Ford GT race car, 2016 Rolex 24 At Daytona

But the real kicker is that the new GT isn't any more fuel efficient than the last GT, which debuted for the 2005 model year, and used a 5.4-liter supercharged V-8.

Adjusted to current EPA evaluation methods, the 2005 GT is rated at the same 14 mpg combined as the 2017 GT.

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So it seems downsizing didn't offer much of a benefit in this case.

It's worth noting that GT buyers probably aren't too concerned about fuel economy, but Ford likely is, at least when it comes to marketing.

2016 Ford GT race car

2016 Ford GT race car

The GT does not wear "EcoBoost" badges on its body like other Ford models, but the name does appear on the engine cover.

Racing versions of the GT also have "Powered by EcoBoost" written on their bodywork in big lettering.

Ford now offers EcoBoost engines in the majority of its models, so it makes sense for the company to want to use its flagship supercar to promote the EcoBoost line.

But if the engine in question isn't very "eco," then it's hard to see the point of using that name.


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