I believe you've meant this one: https://drracing.wordpress.com/2014/01/03/how-close-is-close-enough/ I already posted it in different thread, but perhaps you where referring to this: http://www.racedepartment.com/threads/the-physics-discussion-thread.127125/page-8 Essentially a guy was making C5 mod for AC(he also owned C5 IRL and had access to accurate real data for many Corvette flavours) , but was claiming that, he had to fudge input data (i.e. unrealistic camber) i.e. "The car did not behave the way a C5 would with C7 wheel/tires until I massaged the car with out of normal range camber settings." He also constantly argued and felt offended and in the end, the mod was never released(from what I checked). It's a shame because it looked like it had potential to be one of the best third-party mods. So I would say rF2 over all is most realistic, which I've heard real race car drivers say in the past My feeling is that cars in Assetto usually had good grip, but the problem was (but they've improved) when I noticed car is loosing grip and starts sliding it was more often too late to recover. In some cars it looked like grip is on or off(and car is in weird slide mode). In rF2 there are more fine grained transitions between full grip and loosing traction, it's easier to loose a little grip, but in general it's also easier to recover from (minor) slides.