I have just moved to South Bend, IN and I have had zero luck locating Delo 15w40. All that I can aquire at Napa, Autozone, etc... is Rotella T. I have 8q left of the Delo 15w40 and I was wondering if it would be OK to top the rest of the crankcase off with the Rotella T 15w40.

Thanks!!

 

It will probley be ok, but i dont like doing it. As long as you aren't mixing 2 different viscosities.

 

Use that remaining four quarts for chainsaw bar oil. If your gonna switch brands, switch it all I say. How much are you saving anyway?

 

I would be saving $25 by using the remaining 8q of my Delo and then topping off with the Rotella T.

 

In an emergency you can use any motor oil (syn, petro) to get you in to the shop. Then you should drain and refill with the desired oil. A friend of mine says that Delo and Rotella T are compatible, but I prefer to stick with the same brand/viscosity. I’ve used Rotella T in my truck since new.

 

I did some more research on-line and found little information that supports mixing oil brands in gas motors and/or diesels. I will go ahead and buy 3 gallons of the Rotella T. I don't know what to do with my leftover Delo...