I have a 1999 Jeep Wrangler with a 4.0L 6 cylinder engine. I have been using Castrol GTX High Mileage 10W-30 oil in it. It takes 6 quarts. I was wondering if I can safely use oil which is in an open container I have with the date code K191233 20:03 on it? If so I can buy 5 quarts and combine it...
