This year's 24 Hours of Le Mans race proved once again how ineptly Formula 1's powerbrokers have handled the transition to high-tech hybrid powertrains. Most of the race featured an enthralling battle between the Porsche 919 and Audi R18 e-tron Quattro hybrids. And no one complained about the noise the cars made.

Like F1, sports car racing's elite category—LMP1—features cars powered by fiendishly complex hybrid powertrains. However, F1 powertrain designers, from Ferrari to Renault to Mercedes-Benz, are all forced to build more or less exactly the same thing: a 1.6-liter, turbocharged V-6 attached to sundry energy recovery, energy generation, and energy storage systems.

The LMP1 regulations, by contrast, are framed to reward powertrain designs that deliver efficiency and performance. The internal combustion component of the powertrain must be a four-stroke petrol or diesel engine with no more than four valves per cylinder. Aside from some detail restrictions—regular valves only, and a limit on the supercharging pressure ratio and fuel flow rates, for example—that's about it. The tricky part is that you're only allowed to expend a certain amount of energy per lap. And the amount allowed varies depending on what fuel you use, and how much electrical energy your powertrain is capable of releasing.

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The point is that by allowing engineers more freedom to focus on what they need to achieve instead of telling them how to achieve it, LPM1 racing perhaps offers a greater test of their ingenuity, and race fans much more variety to enjoy. At Le Mans this year Toyota's TS040 hybrid featured a naturally aspirated 3.7-liter, gasoline V-8; Audi's R18 a 4.0-liter, V-6 turbodiesel; and Porsche's winning 919 a 2.0-liter, gasoline-fueled turbocharged V-4. And all were gunning for outright victory.

More critically, though, the LMP1 regulations allow manufacturers to use an elite racing category as a laboratory for technologies that will ultimate improve the cars we drive. "Le Mans racing is quite close to our road cars," says Ulrich Hackenberg, the VW Group board member responsible for technical development. "The transfer of technology is quite organized." Asked for examples, he cites the steel pistons and electric turbochargers in the R18's engine, technologies that will soon appear in diesel-powered Audi road cars.

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Audi's head of motorsport, Wolfgang Ullrich, agrees. "The link between road cars and race cars is there," he says. The future of road car development, like the secret to lapping the legendary 8.46-mile Le Mans at record speed in 2015, is all about making the best use of available energy resources, Ullrich says. Uh huh. But why should we care? "The more efficient cars are, the longer we will be able to enjoy them." Bingo.

In LMP1 racing, high-tech hybrids are cool. In F1, all anyone talks about is the noise they make. (Blame Ferrari: Technical advisers to F1's rule makers originally proposed a turbocharged, 1.6-liter inline-four, but former Ferrari boss Luca di Montezemolo insisted on the flatulent-sounding V-6, and what Ferrari wants in F1, it usually gets.)

Worse, F1's farcical restrictions on powertrain testing and development during the season are a disincentive to manufacturers entering the category. On the eve of the launch of the new hybrid-powered Acura NSX, former F1 world champ Honda, whose under-performing powertrains are the prime reason for the McLaren team's worst grand prix season ever, must surely be regretting its return to F1 racing. Especially as its engineers probably know what needs to be fixed or improved, but can't because the rules don't allow it.

There have been rumors that Audi has been mulling an entry into F1. Ulrich Hackenberg, a man with the juice at VW Group to make it happen, merely shrugs: "LMP1 is interesting to us because while the rules are very tight, it is not so limited in the technology. We don't see that in F1. If F1 allowed technology that was close to our road cars, we would look at it."

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