LMP1 diesel performance adjustment

[gwyllion]

IMSA had made the decision to refueling restrictor from 38 mm to 33 mm. See http://www.americanlemans.com/News/Article.aspx?ID=2276

The current regulations permit the same 90-liter tank on both diesel and gasoline cars but permit the larger restrictor on the refueling rig of diesel cars because of the different viscosities of the fuel.

"The original intent was to permit the full volume of the tanks to be filled in the same time," said Mayer. "However, diesel is a more energy-rich fuel for any given volume. The change that we have implemented means that the energy delivered will be similar, for the diesel versus gasoline, for the same length of refueling. The goal is to ensure that competitors have the opportunity to compete without a quirk in the physics of the fuels creating a particular advantage.

This leaves Audi some room to make tactical decision (more time in the pits refuelling allows more time on the track). And of course the R10 will start the race with a full fuel tank and thus their first stint will be longer

This is an interim solution till ACO and IMSA have measured/calculated the energy content for the different fuels.