"At the moment, we have the situation where a diesel gets 81 litres and a gasoline engine gets 90 litres, but they have the same energy. There is a restrictor in the refuelling rig so the refuelling time is the same even though the diesel is less fuel by volume. That is a very good idea with good thinking behind it. For the fans, they don't have to consider different volumes. It's easy. The car that refuels earlier needs more energy, so the car that is on the track longer is more efficient."
Honda's Clarke has no doubt that racing must adopt green fuel technology if the sport is to continue to thrive.
"I think it's quite clear that, if motorsports is going to continue in the future, it has to become real and relevant and contemporary in the use of green fuels," he remarked. "At the Detroit Auto Show this year, every manufacturer was talking about what they're doing in this area. They all have their favourite fuels and none of them have a single direction. They all have their pros and cons.
"Every manufacturer has put a stake in the ground about what they believe is the right direction and they're all different. So if you want mass participation and competition, you're going to have to embrace multiple fuels."
Of course, the biggest obstacle to delivering alternate fuels to the marketplace is a lack of service stations and systems to dispense the fuel.
"The fact is that the infrastructure for any of those does not exist at a level than can support mass supply," Clarke said. "That's the fundamental problem. Some of them, like fuel cell technology, is not developed to the level that it can support mass production. But still, for all of them, the infrastructure is a major issue."
Ethanol is the most available and deliverable alternate fuel and Honda has embraced the IRL's move to ethanol, building a new, 3.5-litre ethanol-spec engine for this year.
