Originally Posted by wowthisexists
Can anyone speak to the notion that the oil is fouled with water after 2 years?
Not without a UOA.
It really depends on many factors, what vehicle, sump size, temperature, humidity etc.
My truck had a lot of milky oil on the oil cap @ 5000 miles/10 months with mostly short trips, but would do a 100 mile trip (50 miles each way all highway) at least monthly, sometimes 2-3 times.
My oil cap looked like this the day after I had done one of these 100 mile drives:
Oil on the dipstick looked fine, but at some point I had moisture in the oil, and it was still hanging out in the fill tube, so I changed it.
For me on that vehicle (and truthfully all others) I won't do over a 1 year interval.
Oil and filters are cheap (< $20 for Supertech oil and filter @ Walmart if you are wanting to be super cheap).