We all have a stash of old oil bottles sitting on a shelf in the garage. Most car guys think that engine oil has an unlimited shelf life, but the reality is that just like the milk in your ...

But since oil changes happen so infrequently — changing it out every 5,000 to 10,000 miles is recommended – you could find yourself with a bottle or two of unused engine oil for an extended ...

Whether we're talking about the 20-year-old Valvoline oil or the 50-year-old Mobil1, both showed significant signs of oxidation, shaken or not.