So I bought my 95 Runner a few months ago.... The guy who sold it to me said he just did an oil change, and it should be good for the next 2000 miles. So after a few weeks of driving it, with the oil gauge being totally normal, one day it's totally at the bottom of the meter. The previous day it had been totally normal, and I checked underneath my truck every morning to check for leaks and there was never anything. Thinking the gauge was just screwy, I drove it a little bit more, and then went to an auto store to check my oil and buy some if I needed it. My dip stick was totally dry. I put like 4 quarts in, and finally something showed up. That was about a month ago, and now it is unbelievably low again.. I know I'm not leaking. What could be causing the engine to burn oil? I've got the v6, and the guy a bought it from said he just rebuilt the whole engine. I'm like POed right now. The thing only has 145,000 miles on it.

If you were burning that much oil you'd see bluish grey exhaust.
Have you looked at that?

If your engine was 'burning' that much oil, it would be very obvious in the amount of blue smoke coming out of the exhaust. I would more likely suspect an engine oil leak, that only leaks under pressure (while running), and possibly leaking onto the exhaust pipes or manifold and burning off before it hits the ground. This would explain why you don't see a leak on the ground.

I haven't noticed that all, my exhaust has always been clear. I'll have to look around more because I haven't been able to find a leak.