"Altitude Derating - Each model and rating has established
maximum altitude capabilities for lug and for nonlug applications. For higher altitude operation, power settings must be reduced approximately 3% per 1000 ft (305 m) above
the altitude limit for that rating. Diesel engines do not self-derate enough so that the fuel setting can be left unchanged. If they are not reset to appropriate power levels,
naturally aspirated engines may smoke badly and turbocharged engines may suffer excessive thermal and mechanical loading,
resulting in internal damage, without giving external indication of distress."
