Now, it appears the subcompact FT-Bh will become a future Toyota model--one targeted for extremely high fuel economy.
FT-Bh project manager Koji Makino told industry trade journal Automotive News Europe (subscription required) that he expects the car to be built after 2015, but before 2020.
If you're not a fan of the shape, keep in mind that concept cars rarely translate exactly into production models.
Perhaps we're now seeing hints of what that car's successor, a 2017 Toyota Prius C, might look like?
Light and ultra-efficient
The FT-Bh Concept uses a 1.0-liter two-cylinder engine weighing just 130 pounds, paired with a future generation hybrid system. It may be offered in two models: a conventional hybrid vehicle, and one with a larger battery pack and Toyota's plug-in hybrid system for greater all-electric range.
Using a combination of high-strength steels, magnesium, and aluminum, its weight is just 1,730 pounds.
The teardrop shape produces a drag coefficient of just 0.235 using a front end that sends air over the roof and down the sides, and a high, truncated vertical rear end.
That compares to an average of 0.29 for all cars on the market today, Toyota said, and to the 0.25 achieved by its (larger) 2012 Prius mid-size hybrid hatchback.
Every aspect of the FT-Bh has been developed for extreme efficiency, the company said, but at a cost level suitable for the subcompact segment of the market.
100 mpg or more? Well...
The standard hybrid version of the FT-Bh concept is said to use just 2 liters of gasoline per 100 kilometers, which translates to 118 miles per gallon, and target carbon-dioxide emissions of just 49 grams per kilometer.
The plug-in hybrid is even more fuel efficient, using less than 0.8 liter of gasoline and producing just 19 g/km of CO2. That translates to a ridiculously low 300 mpg!
As always, bear in mind that announced fuel consumption targets for concept cars are likely to change before production--and that U.S. gas-mileage ratings are always significantly lower than those produced on European or Japanese test cycles.
Nonetheless, it's entirely possible that a production version of this car would achieve 60 mpg, even 70 mpg, on the combined EPA test.
Bettering the first Insight
The last hybrid car sold in the U.S. with an engine as small as 1.0 liters was the first-generation (2000-2006) Honda Insight.
That car, just a two-seater, also combined light weight and a low drag coefficient with a 1.0-liter three-cylinder engine--paired with Honda's mild-hybrid system--to deliver a combined overall EPA rating of 53 mpg.
Fifteen years later, a four-seat, five-door Toyota subcompact, using a full hybrid system for all-electric running, plus advances in efficiency across every other facet of the car, should easily better those numbers.
We can't wait.