derate

Common practice is to derate 20 degrees Celsius from the maximum rated temperature limit.

"If your turrets aren't locked fore and aft, I'll derate you right now."

The Dana 80 has a GAWR up to 11,000 lbs, however it is common practice among manufacturers to derate Dana 80's.

Adele switched on the console and started to sit, but as the newly installed equipment hummed to life she heard Woetjans bellow, "Hargood, if you don't take three seconds off your time, I'll derate you to Landsman.