A. Soot loading in the oil is caused by fuel combustion by products and can be impacted by operating conditions, engine condition and the efficiency of the fuel injection system. The oil does not produce the soot but it must manage to disperse the soot to protect against oil thickening, oil filter plugging, increased engine wear, increased oil consumption and poor lubrication during cold engine start-ups.
Synthetic oils which have been formulated with a robust soot dispersant system such as CITGO CITGARD 700 Synthetic Blend and SynDurance Full Synthetic 5W-40 heavy duty engine oils and have a patented Soot Arrest dispersant system have demonstrated in field performance to optimize soot control better than conventional engine oils.
It is recommend that you consider an oil analysis program that will report the level of soot in your oil and you can track the impact on oil viscosity and engine wear. This will provide you with the best answer to your question in real time evaluation of your operation. CITGO offers an oil analysis program called LubeAlert that is provided at no testing charge (you only pay for the postage) when you use either of the products listed above.