American manufacturers tended to use enormous rotors in the early days, assuming that they would last the life of the car. Monsters, most of them, with cast hub (not separable like the Benz or BMW/Volvo, etc). Very thick, so there was lots of metal to turn them flat again, and the pads used at the time didn't wear them like the semimetallics Benz uses do.

Much heavier and much more expensive -- I've seen them cost upwards of $100 and that was twenty years ago.....

European makes always used "disposable" rotors to keep the unsprung weight down, something of very little concern to Detroit in the 60's and 70's when American iron still handled like a wounded whale.

That changed, and they are all simlar today.

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!