Re: 4 stroke oil
auto oil will work in a pinch. But you really should use an oil that is designed specifically for outboards. These will be marked as "FC-W" rated oils and can be bought at any marine dealership. Nissan/Tohatsu/Honda/Yamaha/Merc/Suzuki, etc all have "FC-W" rated oils available. These oils are designed for outboards & like Paul says, have additional corrosion/rust inhibitors. They also maintain their viscosity better even if gas mixes with the oil (see threads on "making oil"). They also work better on motors that run at high rpm's (remember outboards are running at 5000-6500rpm...cars generally don't). But if you're someplace where FCW oil isn't around and you absolutely have to add oil now and can't wait, auto oil is better than nothing.
