Don't misuse the word canned (that gets misused way too often). It would simply be calculated with an algorithm they "guesstimate," much like a lot of car variables the guys must speculate like center of gravity and a lot of other parameters that get hailed as "perfect" "best of all" etc. Some developers do get lucky to have the manufacturer share their formulas for certain things, such as AC with Pagani or LaFerrari.
yes, my understanding of TC in all sims is that its meant to be some kind of approximation, not an actual simulation of the system.
... very interesting: http://newscentral.exsees.com/item/09f8dd281c92c93a1436a46799eb5968-56f1a2d5d1f9218168e99db87eff18ff
