S-K Railroad and Marine Engine Oil is a superior, Low Ash, Heavy Duty engine oil formulated to address the emerging fuel and emission standards coming to large, medium speed locomotive, marine vessels, and electric- powered generators. It is formulated with a blend of stable synthetic and premium mineral base stocks for long-life performance in 2 and 4 stroke Gen 6 (and all previous category) engines used in a wide range of marine trunk piston, railroad, inland marine, mining and stationary engine applications. Patented non-chlorinated technology is future proof for Gen 7 emission requirements.