When Audi won the Le Mans 24-hour race last weekend in a hybrid powered car there was high praise for their efforts — and with big manufacturer presence on the sportscar grid is Formula One missing a trick?
The energy efficient element of the R18 e-tron quattro's engine was actually engineered by Formula One, using a hybrid technology design developed by Williams Hybrid Power (WHP) with origins in the F1 team's original flywheel KERS system.
Formula One pushes 'Hybrid KERS' to play its green credentials card - yet the way it is used does not really reflect the opportunity it can offer.
As with the Le Mans system, the F1 KERS feeds heat energy generated from braking to a 'storage vessel' by converting it into a different type of energy — in F1's case it charges batteries, in Audi's Le Mans car it spins an electronic flywheel accumulator.
But rather than using the F1 solution of storing energy up for an extra push-button power boost, the Le Mans approach is to release KERS energy on acceleration as an integrated part of the overall drive train — enabling the car to save more fuel for every lap.
In Formula One, KERS has always been a controversial issue.
Initially introduced as an 'optional extra' in 2009, it was scrapped for two years at the end of that season as part of a gentleman's agreement, with teams ruling it too heavy for the power benefits it gave and choosing not to develop it.
In austere times, the associated high cost, typical of both advanced technology and early adoption, gave teams the perfect get-out clause.
When it returned, with a more balanced benefit, it was still expensive to develop but it has proved to be a successful addition to the sport. But it has also demonstrated an element of closed thinking on the part of the F1 engineers — with Le Mans going in the opposite direction.
Last weekend's hybrid Le Mans win showed Formula One's claims to be at the forefront of technology are certainly not exclusive.
The Le Mans regulations called for reduced power engines this year but opened up to accepting new power sources and energy recovery — they're even open to allowing in a car as radical as the Nissan Delta Wing.
In contrast, the Formula One regulations are — some would say quite rightfully — much more restrictive. But in being so, it is perhaps making itself less attractive to the manufacturers that once held it in such high acclaim.
The list of entrants at Le Mans - despite the departure of Peugeot for financial reasons this year - is impressive and they're all there genuinely to use it as a proving ground for technology.
Alongside Audi and Nissan, Toyota made their return to the series this year, also testing a hybrid development that had strong relevance to road car technology, while Honda Performance Development (HPD — a part of the American subsidiary of Honda) also got involved.
The permitting of four-wheel drive — another new opening Le Mans has recently explored — enabled Audi to combine the two technologies of 4WD and hybrid in an innovative drivetrain that, they say, has direct reference to future production line products.
Indeed, they confirm: "The first experimental vehicles with the electric four-wheel drive e-tron quattro system are already being tested with a view to possible high volume production."
The kinetic energy from the front axle during braking drives a motor generator unit that in turn accelerates a carbon-fibre flywheel, which runs in a vacuum. After the corner, when the driver accelerates again, the system delivers the energy to the front axle. The regulations allow 500 kJ of energy to be transferred to the front wheels between two braking phases, and the gears adapt the transmission ratio during acceleration and braking.
At the back, meanwhile, an independent diesel V6 engine with 510hp powers the rear wheels - and the two independently powered front and rear axles are synchronized using electronic control, without driver intervention.
As in F1, it's all about a compromise between weight, packaging, performance and regulation constraints — but Audi clearly made it work. And the fact they were allowed to could be a pointer to how future technology should be approached in Formula One.