The 5qt jug I bought the other day had nothing stamped with ink just a few numbers stamped right into the plastic on the bottom of the jug. There was dust on the jug but it was the only one left. A jug of the same stuff at an auto parts place had a code stamped in ink on the front side at the bottom. How can you tell the expiration date on Mobil 1? Without codes on the jug how would you know if it was still good?