Originally Posted By: kschachn
That can't be, right? I mean the same company can't sell the same item under two different names for two different prices, at least you couldn't 20 years ago when I worked for company that sold lots of "stuff". That was illegal for us to do so. Our products had to be demonstrably different.
Originally Posted By: CATERHAM
This came up in another thread a while ago on the real difference (other than marketing) between regular M1 5W-30 and EP 5W-30. IIRC the conclusion was that they're the same oil.
Not sure. The warranty is different between the 5w30 M1 and 5w30 EP, so you might be buying the warranty. I don't think all Mobil products are that way, but if you have a 5w30 that is very good, it makes sense there wouldn't be much to change for the EP formula with its warranty.