This question should probably go into the oil analysis section, but here is one answer:
Oxidation causes an increase in viscosity and promotes acid formation. Oxidation is caused by the absorption of oxygen molecules, and oxygen molecules cause decomposition of base oils and additives. Oxidation is more rapid where you have high oil temperatures and increased moisture.
Nitration causes sludge and varnish, and is primarily due to blowby gasses from the combustion process being injected into or mixed with the oil. Poor ignition/combustion and ring sealing may contribute to nitration.
Sulfation of the oil is primarily caused by sulfur in fuels, and secondarily by some of the sulfur-containing additives.
In any analysis, find out what the scale is. If the analysis number is say Nitration 10% on a scale of 100%, then nitration is relatively low.
Trending of UOA's are the most important part of analysis. For example, if you make a mod to the engine and the nitration goes to 70% after the mod, you got a problem.
The other important point for analysis is engine and oil global averages for your car's engine and oil(s). This is where the laboratory and the analyst, such as Terry Dyson, can help you, since their experiences and informational databases help to interpret the specific analysis.
Ask questions of both the lab and the analyst. This is what you're paying for.
[ January 17, 2004, 03:11 PM: Message edited by: MolaKule ]
