Another thing that really shows off the perfection of the physics modeling in this movie are the two dirt-track races that Lightning and Doc get into, both of them have been seen in the various previews, but seeing it on the big screen, you really sense the accuracy of the physics modeling…
In the first clip, Lightning’s roaring along at WOT (Wide Open Throttle) along the dirt track, the suspension is flexing and responding accurately for dirt track conditions, there’s a palpable sense of speed, Lighning turns his tires hard left to take the corner…
And he’s carrying too much speed into the turn, there’s not enough grip on the front tires to overcome his inertia, so he flies off-track, front tires pointing left, while going straight into the Prickly Pear cactus patch, front tires completely ineffective due to nonexistent traction…
As a car guy, as soon as i saw Lightning tearing down the dirt track heading into the corner, i said to myself “he’s carring too much speed into the corner, he’s not gonna’ make it”, the animation and physics modeling was just right…
Later, Doc Hudson drives the same track and countersteers into the turn and controls the rate of turning/sliding with the throttle, powersliding through the turn, once again, the physics model of a powerslide on a dirt track was absolutely spot-on, right down to the clouds of dust kicked up during the powerslide, and the slower revolutions of the front tires as Doc carves the turn in the dirt…
In Radiator Springs, when Lizzie, the old Model T Ford (who was seen earlier in the Boundin’ short for The Incredibles) is sleeping, her “snores” are an absolutely perfect recreation of the idle sounds of an old Model T…
The Tractor’s engines have the slow, loping idle of a large diesel engine
The King’s crash in the final race was wincingly, jaw droppingly real, there was an audible gasp from the audience when he started rolling and rolling and rolling, the entire audience winced in sympathetic pain…, and this was in reaction to a CGI rendered car, i guess it’s safe to say the audience was able to suspend disbelief…