Originally Posted by IDZRVIT

Dino engine oil is not as hygroscopic as synthetic oil. Regardless, the amount of water absorbed by the synthetic oil won't do any harm such as corroding the engine's internal components to the point where it will fail as long as the oil is changed on a regular basis, even if it's yearly for synthetic oils. That said, then why not just use dino oil that doesn't readily absorb moisture? The oil debate is over stated because even the cheapest dino oil that truly meets API specs will effectively lubricate your engine under normal use and when changed regularly will probably outlast your ownership of the vehicle. Car manufacturer's want you to change your oil more frequently, at your expense of course, as a little bit of reassurance that the engine will not fail prematurely and avoid a warranty claim as well as make more money for the dealership's service department. I doubt there is any scientific evidence for engines lasting any longer by changing the oil more frequently but members here are welcome to present the facts otherwise.

I once owned a plain jane '67 Camaro that sat in an unheated garage in Newfoundland, Canada (all kinds of moisture laden air in that place) from 1981-1983 with used dino oil. Started her up and away it went. The only damage caused by neglecting her for two years was the valve seats dried out and cracked. I know this is not scientific but based on that experience I don't waste my money on specialty oil companies such as Redline, Amsoil, Royal Purple, etc as there is no added protection or proof that will make my engine last longer or perform better for the length of time I will own my vehicle. Now if I raced my car and 1/4 mile or lap times were reduced solely on the type of engine oil then I would use the specialty oil. So, ask yourself this in your decision to buy oil - do all NASCAR team owners use the same oil? If they do then I'll buy that brand because it's obviously the best out there. If not, then it really doesn't make a difference what oil you select especially for normal street use.

I for one will save my money and change the oil according to the manual for my type of driving i.e. every 7500 miles. When the vehicle is out of warranty it will be once a year with synthetic provided I don't exceed 15000 miles or so.