9 months, 3,000 miles. My posted used oil analysis showed NO water dilution. Condensation only has two potential routes into the sump of an idle engine: intake tract or exhaust tract. In either case moisture would have to traverse past the piston rings, which make a pretty good seal against the cylinder bores at normal atmospheric pressure, or the PCV valve, which itself is spring-loaded in its closed configuration unless the engine is running. Water is a natural byproduct of hydrocarbon combustion. If there's water present in a used oil analysis report, it's from accumultated blowby past the rings because the engine was not always warmed sufficiently to evaporate it off and blow it out the exhaust pipe during operation.