Diversity is a good yardstick. The key to Le Mans' success in influencing real-world motoring technology is diversity, even perversity. For the motor industry, Le Mans remains both a public stage and a sharp-end testbed that they can no longer find anywhere else in motorsport. That function certainly doesn't exist in F1 any more, because F1 design and the race format are so far removed from everyday issues as to be essentially meaningless. In fact F1 barely does diversity at all any more, except on a molecular level.
The closest F1 came to true freedom in modern guise was the sometime choice between turbocharged and non-turbocharged engines, but it was invariably a financial necessity and long since gone. So what you get has precious little relevance to any road car.
F1 had its fleeting excursions, like gas turbines and four-wheel drive, but anything vaguely esoteric was far more likely to be banned than applauded. Viz ground-effect aerodynamics (including Gordon Murray's Brabham "fan-car" and Colin Chapman's twin-body Lotus), or more recently McLaren's F-duct and everybody's "blown-diffusers".
You might also notice, incidentally, that virtually all such innovation in modern F1 is aimed at aerodynamics, not at the noisy bits; and what's more at areas of aerodynamics (like extreme downforce) that have sod-all relevance to you and me on the A272.
The problem is the rules. F1's are so stifling that the key skills are in exploiting the loopholes and having a good legal department. Le Mans' rules, on the other hand, are also prescriptive, but enticingly loose. So you won't break them just by being different. All F1's recent innovations have been to improve the spectacle (and largely for TV, not for the faithful in the bleachers). KERS, DFS, tyres with the life of a butterfly and "pit-stop strategy" all add interest, but diminish the purity of what still bills itself as the pinnacle of the sport.
The strategy at Le Mans is to stay out of the pits as though they were on fire. A set of tyres that lasted five laps would have them rolling in the aisles here (even though one lap is eight-and-a-half miles). One of the reasons Audi won last year is that it made one set of Michelins last five stints (that's five re-fuelling stops – which are what really drive Le Mans pit calls).
There are crossovers, of course: nobody ever won Le Mans (though a few have lost it) by badly timed or clumsily executed pitstops. In 2011, when two massive accidents reduced the end-game to one surviving Audi versus a swarm of Peugeots, the leading Audi and chasing Peugeot came into the pit-lane seconds apart, for one final stop, with 35 minutes of the 24 hours remaining. Both needed fuel, Peugeot a fill, Audi a splash. The Audi needed tyres, after a last-gasp puncture; the Peugeot could probably have used new rubber too, but didn't take it. A Le Mans tyre-change isn't eight men, four wheel-guns and three seconds; the rules say two crew, one gun, you can't do it until fuelling is complete (by gravity), and engines must be switched off during all pit work – so you'll want it to start on the button, too.
Peugeot were at the entry to the pitlane, Audi at the exit, a couple of hundred yards apart. Literally as the Peugeot started to roll, on used tyres, Audi team manager Leena Gade called for new ones. The Audi emerged 7.8 seconds ahead, on a slippery track but sticky rubber, survived the threat of rain, slower cars and some aggressive encounters with their opponents, and won by 13.4 seconds. And it wasn't engineered for the television.
Michelin has an endurance racing initiative called the Green X Challenge. It's not some big bloke in a superhero suit helping kids across the road, it's about recognising race efficiency, notably fuel efficiency. It is about to append tyre efficiency. The French company says that a single set of road car tyres represents a "well-to-wheel" energy equivalent of more than 25 gallons of fuel, and each set of race tyres significantly more. So the fewer they can use, the happier they will be (and the more competitive). 2012's winning Audi used "only" nine sets (but that included various weather changes); that five-stint set covered 454 miles – that's two and a quarter Grands Prix. Michelin says its latest generation high-performance road tyres have double the life expectancy partly because of lessons learned at Le Mans.
In fairness to Pirelli, in real life its aims are undoubtedly similar to Michelin's, and its technical ability is second to none, but for the sake of the show the Italian company is obliged to use it in developing F1 tyres that don't last as long as a bag of crisps. No wonder outsiders are confused. And just as an aside, there are two manufacturers head to head here (Dunlop is the other one) and up to four in the wider world of European and American Le Mans Series races. That helps, too.
There was a time when Grand Prix racing had a similar ethos to Le Mans – a proper, long-distance test of man and machine. The first ever to bear the title, after all, was held at Le Mans, in 1906, on a 65-mile road course. And 780 miles, even split over two days, was a proper test (won by Renault). Even in the 1940s they would have laughed at a 200-mile, two-hour maximum GP format; that's three laps of the original 1906 circuit. But Le Mans is still 24 Hours, and 24 hours is still two laps of the clock in anybody's money. In fact while F1 is increasingly about tyre conservation, Le Mans has gone in the opposite direction: it is a 24-hour sprint, and has been for years.
There's a question of how you use the power, too. In 2006, a Honda F1 car reached 415kph (almost 258mph), the highest speed ever recorded for a modern F1 car, but they had to chuck away the wings and other aerodynamic aids, and give it the space of the Mojave Desert. Fact is, an open-wheel car looks racy but has the aerodynamics of an open wardrobe, and you don't see many on the road, do you? But in 1988, pre-chicanes, a Peugeot-powered WM coupe topped 407kph (253mph) at Le Mans, on the tree-lined part of the circuit that in everyday life is the N138 towards Tours. And it could still go around corners.
It's no use asking an F1 team to develop your lighting systems, or weather equipment, or air-conditioning (Le Mans coupés are obliged to have air-con if they can't keep the cockpit temperature below set limits without it). And talking of coupés, don't bother asking F1 boffins whether a coupé is better than an open car, a petrol better than a diesel, a diesel/flywheel hybrid better than a petrol/capacitor hybrid. Unless they follow Le Mans. And don't even think about mentioning production-based classes...
2012's Le Mans 24 Hours had the DeltaWing "trike", exploring the theory of light weight, low drag and not much power; and the numbers stacked up, until the car did, too (through no fault of its own). This year we should have had the hydrogen fuel-cell-powered Green GT, but it wasn't ready in time. Next year Nissan will have a revolutionary "electric" racer.
These are all in the spirit of Le Mans' Garage 56 rule, which encourages one car that doesn't fit the rules proper to compete outside of them – as the gas-turbine Rovers did in the 1960s. Over the years, Le Mans has welcomed air-cooled two-strokes, two-stroke diesels, eight-piston four-cylinder two-strokes (don't ask), front-drive, all-wheel drive, supercharging, turbocharging, rotary engines, biofuels and proper racing hybrids. On the output side it has contributed to everything from windscreen wipers to waterproof electrics, disc brakes to radial tyres and proper lighting – and most of all to performance with efficiency and reliability.
The FIA puts on 20 Grands Prix a year, but they're still only planning one Le Mans. The good news is that it only takes one.