Check DSC out, they phoned up Henri and asked him straight out and he said Loeb didn't know what he was talking about.
I think this reflects more on the quality of Autosports journalism.
Lifted from DSC I hope they don't mind.
A diesel-powered Pescarolo? Quoi?
Time to talk to Henri Pescarolo.
“I don’t know what Sebastien means,” says Henri. “For sure we won’t have a diesel-powered car. Both of our cars will be Judd-powered. I know that Sebastien is not happy with the diesel rules, and hopes that the rules will change for next year. This year he is going to concentrate on his C4.”
So that clears up that puzzle.
NB. Claude Foubert points out that it seems to be a simple translation error: the original French text makes no reference to a Pescarolo diesel, but suggests that the five diesel cars and the lead Pescarolo will be highly competitive.