Quote:
Here is the rest of the story from an email I have from Shell:
All of our Shell Rotella multi-grade viscosity products are
completely compatible with one another in any ratio. A 50/50 blend of Shell Rotella T Triple Protection Oil SAE 15W-40 with our Shell Rotella T6 Synthetic Oil SAE 5W-40 would be perfectly acceptable. You could then switch to Shell Rotella T5 Synthetic Blend Oil SAE 10W-30 whenever you desire. Thank you for your interest in Shell Lubricants! Regards, Edward A. Calcote Staff Chemist Shell Lubricants US Technical Information Center