How altitude affects diesel engine performance

Essentially, the higher one goes the thinner is the air. If you go high enough a carbureted engine stops working, that's at about 4000 meters or 12,000 feet. Any higher than that you'll need fuel injection. Try climbing a hill at that altitude, and most of us will be puffing and panting after 50 meters or so.
So too diesel engines lose power with altitude.

Rough altitude power corrections
Detroit NA 2-Stroke engines:

• 2.5% Reduction in power per 1000 ft
• 0.8% Reduction in power per 100 m

4-Cycle Naturally aspirated engines:

• 3% loss in power per 1000 ft
• 1% loss in power per 100 m

All turbocharged engines

• 1.5% loss in power per 1000 ft
• 0.5% loss in power per 100 m

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