This was a quote from this week NORIA newsletter, wanted to get the forums take on whether a crankcase falls into a "clean,dry" enviroment?
"From "Basic Handbook of Lubrication"
"he use of a synthetic oil may allow oil drain intervals to be extended. In a clean, dry system, a synthetic oil may allow for extended drain periods (double or triple the drain interval of a mineral oil is possible) if the mineral oil was being changed due to oxidation. If the oil drain interval for the system (with mineral oil in use) was set due to external contamination entering the oil, then the use of a synthetic oil will not allow the drain period to be extended. Oil monitoring by laboratory analysis is the key to understanding the situation."
"From "Basic Handbook of Lubrication"
"he use of a synthetic oil may allow oil drain intervals to be extended. In a clean, dry system, a synthetic oil may allow for extended drain periods (double or triple the drain interval of a mineral oil is possible) if the mineral oil was being changed due to oxidation. If the oil drain interval for the system (with mineral oil in use) was set due to external contamination entering the oil, then the use of a synthetic oil will not allow the drain period to be extended. Oil monitoring by laboratory analysis is the key to understanding the situation."