[A. Patriot]

About diesels and altitude, in the 1980’s a had a brand new Datsun diesel kingcab pickup truck that I drove to the top of Pikes Peak in Colorado. I thought I wasn’t going to make it to the top and there was a 10 foot long plume of soot coming out of the exhaust. Maybe there was no altitude sensor or something like that on it.

[Red Badger]

lower oxygen level at that altitude caused incomplete combustion, so more soot.........

[right way right]

Your Datsun did not have a turbo. Turbos were often called “altitude compensator's” by some manufacturers when they first were developed and used in military applications.

When air density is lower in high altitudes the turbine simply turns faster because of less resistance in pushing air that is less dense . It will compensate up to he point that it is capable of. In other words,lightly turbo or non turbo (normally aspirated) engines will still smoke at high altitude.

I had a 92 non turbo 7.3 ford diesel in a F 350 and would make service calls up to Paradise (Mt Rainier WA)and it would really leave nice black cloud. I really felt bad when I passed bicycle riders on the way up. Poor Bastards!