Supercars. The very word has become a bit played out, and words like "hypercar" or even "ultracar" are being used to try to inject some feeling of the mind-blowing performance of the upper echelon of modern high-end sports cars. But a few carmakers are beginning to realize that all-out performance isn't the only goal worth pursuing.

Audi's R8, for example, or Porsche's 911 Carrera exhibit a more sensible balance toward peformance and luxury than, say a Lamborghini Murcielago or even a Dodge Viper SRT10. With 420 horsepower from a naturally aspirated V-8 engine, the R8 is a mid-engined sports car with good, but not amazing, power, it handles brilliantly, and it doesn't break the bank. It's balanced.

So talk of the BMW Z10 sporting a 3.0-liter twin-turbocharged in-line six-cylinder engine makes a very enticing sort of sense. The latest rumors of the car, which pitch it as a mid-engined sports car with 450 horsepower and about 350 pound-feet of torque, also make it plain that it has no pretensions of chasing down the wildest and wickedest in the supercar arena.

That's a perspective that shows a longer view of things, with the days of completely unrestrained works of automotive engineering stretching toward dusk. Gordon Murray, legendary engineer and designer of the McLaren F1, recently voiced his thoughts on the matter, concluding that the future of the high-performance car must also be a green one.

So the Z10's rumored relatively lightweight design goal--considering modern safety requirements--at 3,300 pounds, making use of aluminum, carbon fiber and other composites, makes a lot of sense. As does the choice of a small-displacement, forced-induction engine. The dual-clutch transmission is almost de rigeuer for any sporting vehicle these days, but also lends more efficiency than a standard automatic.

Taken in light of the upcoming Vision EfficientDynamics concept as well, the Z10 design parameters could end up being even greener, though integrating a large amount of EfficientDynamics technology, particularly cutting-edge features, could prove too costly for production. BMW is thought to be targeting a similar price point to the standard Audi R8, at around $110,000.

The Z10's aesthetic design cues are likely to borrow from the M1 Homage concept (pictured), as well as from the Vision EfficientDynamics concept coming to Frankfurt next week, though it will also doubtless be grounded firmly in BMW's latest corporate face as well. An aggressive "face", with a strong kidney grille, slanted headlights, big air ducts and strong character lines along the sides will reflect the car's performance-focused nature.

BMW has until 2014 or 2015 to get its little green ducks in a row, however, so much may yet change. There's even talk about a V-6 engine replacing the classic BMW in-line six, though that's not likely to meet a warm welcome from BMW purists.

[Automobile]