Just picked up 4 Gallons of Mobil Delvac 1300 Super 15w40 at WM. They also have a rebate going at Mobil for $4 on each gallon up to 5 gallons.
I also found a nice, out of the way, Advance Auto Parts store in Passaic, NJ with the shelf full of Formula Shell in 5W-20, 30 and 10w30 and 40. Needless to say, I cleaned them out of all the 5W-20 and 5w30. 24 quarts of Formula Shell at $1.75, marked down because it would not move. Well, it moved tonight....right into the back of my 4Runner to keep the Mobil Delvac happy. Just like today....I mixed the Shell Rotella 10w30 with the Formula shell....5w30.
Yesterday, I had called Shell products customer service to see if these two oils, Formula Shell and Rotella, were compatible to mix....they informed me that they form a very happy marriage when mixed together and I could not pick two better oils to mix.
Tomorrow, I plan on doing the same with the Mobil Delvac 1300 Super. I will mix the Delvac, 15w40, 50/50 with Formula Shell 5W-20 this weekend. FWIU...All of these Diesel oils run extremely well in gasoline engines and can be mixed with motor oils of your choice. In fact it's very difficult to tell the Diesel Dino apart they are so similar. The diesel oils are high in detergents and great base oils with PAO. All the oils are rated API-SM and the diesel oils are API-SM and CJ-4. Formula Shell is loaded with Moly and has lots of punch in the add pack. They should mix well together even if One is Mobil and the other is SOPUS.