Need answers quick! changing oil now... couple questions

Yep. Oil coats every internal surface. You'd die of old age before all of it could drain out.

 

The correct amount of oil for the engine application is at "full," below that, to the low mark is acceptable, but low, and not as good. This is how the full mark comes to be chosen at the engineering dept. If better was a 1/4 inch down, they would put it there and say the engine is thrifty on oil changes. There are probably many reasons for the "full" mark, but a couple are oil longevity, oil starvation under certain conditions, safety room for oil consumption, and oil temperature. As for economy, at "full" it isn't less. There isn't more friction, there isn't foaming, there isn't anything but oil pumping where it is supposed to go and returning to the pan. If folks think they know more than the engineers who designed the engine, more power to them.

 

So what's that bottom mark for?

 

I'm in the process of changing my oil now. I've pulled the drain plug and drained the oil. However, it does not look like the drain plug had a gasket on it. Is it something that could realistically be missing without leaking before? Do they not all have them? Or could I just bd missing it? It looked like a regular drain plug, mating two flat surfaces.

This is the first time we are changing the oil on my '08; I just bought it used in Dec.

 

It is certainly possible that the old drain plug gasket is missing. Make sure that the old gasket is not sticking to the drain pan.

I recommend that you use a new drain plug gasket when replacing the drain plug.

 

Thanks! I'm searching the oil pan now. If it's not there, it'll be back down to the auto parts store again.

 

With my Prius, the drain plug gasket would sometimes stick to the pan. Carefully inspect to verify it isn't stuck there

With my FJ, the drain plug gasket almost always sticks to the pan