Cal Club Autocross Forums

Stupid question: does motor oil degrade over time like gas? I have a case of Mobil 1 synthetic that's been sitting in my garage for about 9 mos, and I just changed my oil, so it's likely to suit there an additional six or so. Will it break down and be unusable by then, or is it okay?

Motor oil has a shelf life of, oh, about a million years or so

Kurt Rahn wrote:Stupid question: does motor oil degrade over time like gas? I have a case of Mobil 1 synthetic that's been sitting in my garage for about 9 mos, and I just changed my oil, so it's likely to suit there an additional six or so. Will it break down and be unusable by then, or is it okay?

If your worried you should give it away to a corvette driver who runs mobile 1, that could ease your mind. But like QV said, if you use it this decade you should be fine.

The oil itself will deteriorate sitting on the shelf since the container can never be 100% sealed and over time it will collect moisture and cause it to break down. I don't know how that affects synthetic oil but that's the case for conventional oil. I don't think sitting on a shelf for a year or four will do enough harm that I would worry about it since its not exposed to sulfur or carbon or anything that can cause the oil to acidify. Just make sure that first run is long enough that the oil gets to temp.

Thanks, guys.