content: My Saab always had a semi-synthetic in it. Today I put RP in and WOW! The quite noticeable ticking sound that had been in the engine for the last 3 years is gone. SMOOTH running now like never before. And if you go to the Wmart for an oil change, they will charge you the same for this as any other synthetic change, even though it averages about $3-4/qt higher than all the other synthetics.