I don't think it right to me.
My former 01 F250 2wd with 5.4L we was cruise at high speed that had rpm up 3,500-4,000. AC were blow FREEZE so I must be image it stay ON all times what rpm but Never try above 4K rpm.
My 00 F350 diesel had 214K. When I got I need put about 2 cans of R132A...