When I run 50/50, I notice a slight increase in smoke opacity at the rev limiter and at cold idle but nothing out of the ordinary within the normal RPM range.

By opacity, I mean the smoke is darker. I get smoke at the rev limiter or about 4500 RPM even on D2 but the oil makes it a little darker.

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1991 F250 super-cab 7.3 IDI. (rebuilt by me) Banks Sidewinder turbo, hydroboost brakes, new IP and injectors.
2003 S430 - 107K
1983 300SD - Tanoshii - mostly restored ~400K+.
1983 300SD - Good interior. Engine finally tamed ~250K.
Monark Nozzle Install Video - http://tinyurl.com/ptd2tge