That's been on wikipedia for a long time. I doubt it's true tough.
Then again who knows what the devs have been testing internally, but they do seem to be mostly a "when-it's-done-release-it" kind of types.
... Back in the older versions (pre-released S2 / Leaked S2 beta), the surface beneath the tyres was listed, and the ramps were said to be "ice", so that's likely where that info has stemmed from.
I think it had something to do with the Trophee andros edition of the LX8. Or was it the lemans prototypes at LFS-lemans with temperatures going below zero...