[Overdrive]

I think part of why people are telling you to leave the oil in the vehicle and that they haven't experienced problems over the winter in doing so (myself included, ungaraged and simply car-covered) is because they're trying to say that it's not really necessary to go to the lengths you're intending to store the car over the winter. It's your car and your decision, but while people may not have an answer for your exact question of problems that could arise from what you want to do, they're giving you an alternative that will not be problematic, contrary to what you have read, and will save you time, money, and worry: leaving the car stored as is with a fresh oil change (if you choose), some fuel stabilizer, a battery maintainer, and pat on the head. If I can be a bit blunt without meaning to offend, I think you're really going overboard with that storage unless you really intend to have the car sit for more than a season or two.

Even then, my car sat on a dealer's lot right here in CT for 5 years with whatever oil was in it and 1/4 tank of gas before I became the owner. I used to see the car a lot, and I think it may have moved twice to a different space in the same row on the lot, but still, it just sat. 5 years of both weather extremes, nevermind dive-bombing birds (an entirely separate issue), and when I came along and asked to take it for a test drive, the car started up and drove just fine. The oil that was put in it the day before I took it home stayed in it from June 2010 to June 2011.

If you happen to live anywhere near me, you may remember that this past winter in between those two Junes served us with 3-4 feet of snow in one good storm, followed by another that threw another foot on top of that, and to top it off both storms' snowfalls proceeded to freeze over and start collpasing roofs of homes. Temperatures were freezing or lower for weeks at times. My car suffered through that just fine (that isn't to say I wasn't worried, though). I just hooked it up to the battery maintainer overnight once every week or 2 (I only cleared a path to the driver's door, the rest surrounding the car had to melt), and she started up just fine once the thaw came, and drove fine for a few more months until it came time to get some maintenance done right about the same time the year limit I set for myself on oil changes came around.

Like I said before, I figure a good quality synthetic oil that's going to cost you nearly $10 a quart or sometimes more is not going to be unable to handle temperature extremes. That's why we're paying so much for it, among other reasons, but that's certainly one of them. I want my oil to work whether it's 10 below or 140 outside. I'm sure some degradation is going to occur, as is bound to happen just from the substance existing, but the majority of us don't really question how long a quart or 5 quart container has been sitting on a store's shelves before we go tossing it into the car, do we? Nor do we know the conditions the oil has been stored and transported in prior to landing on the shelf where we buy it. How can we gauge just how much life the oil has lost in those cases prior to our use in a vehicle? If it were really that serious, then some supplier, somewhere, with a poorly or non-temp controlled warehouse up north full of motor oil is sitting on a huge lawsuit.

Germany sees nice extreme winters too, and that's where these cars were expected to be driven. I'm sure there's a decent number of folks in Germany who drive their Boxsters year-round and don't worry about oil degrading due to the cold.