That's over the course of a 2 hour race, when the difference in speed between the fastest and slowest car is about 1-2 seconds per lap on a 3 minute lap.

Nobody passes another car like they're standing still. But, often a better car can brake just a bit harder and get better position on a corner. Or it can go just a bit faster on the straight and be half a car-length ahead at the end of the straight.

The way these things are depicted in movies is more like the races you sometimes see where it's a pro racing driver vs 100 amateurs.

I'm referring more to the way it was depicted in the film. He just ripped by everybody, even on the straights. IRL, coming up from the rear is a long battle. Also, I'm pretty sure the plot of the movie was entirely fictional.