I had my oil changed yesterday since its winter here in MN and didnt feel like crawling under my car and doing it myself. One of the concerns on the inspections was that no oil registered on the dipstick. The service manager said that the car could of been burning oil since they couldnt find any leaks. I have never noticed or smelt burning oil and am wondering if the increase in cold weather could of caused it like he said at the shop (burning oil). How can I prevent it from burning oil?