I changed my oil about a month ago. I checked it today randomly and about 1/2 a quart is gone I'm guessing. I checked everywhere for leaks and there are none, no smokes comming out of my exhaust, and there's no oil on my plugs or wires. I romp on my motor pretty hard that's the only thing I can think of. My vtec engages normally. I just don't know. Does old oil burn kind of fast? Because there might have been close to a quart left in the pan that I just couldn't get out because I live on a hill so there's an incline.