[polizzio]

Even Mobil 1 recommends replacing their full syn oil annually, regardless of mileage driven.

Its not so much the water in the oil, its weak acids created in the oil by combustion blow by/contaminants. Small (read normal, not leaks) amounts of condensed water from combustion process will vaporize when the car is driven regularly and the engine up to full operating temp. The ethanol in 10% blended gasoline is terrible for engines and fuel tanks when sitting up. Corrosive.

walmart stores sell Supertech full synthetic 5-30 oil for approx $16 a gallon. What I now use. Its walmart brand but is produced by one of the major lubricant manufacturers and bottled for walmart. Mobil 1 is $24 a gal for comparison (what I used before). Order some wix or GM filters from amazon.