Royal Purple? I installed 5W-30 in my 2002 Outback about three weeks ago. I've not experienced from an oil change such a difference in feel in an automobile. The car is distinguishably quieter, smoother running and peppier.
That said, I had an interesting experience with RP tonight after having checked the color of a quart of M05 GC I had purchased a couple of weeks ago. I hadn't done the GC color check yet only because I hadn't been fully exposed to the Elven plague that's hit the BITOG masses (I may now be coming down with a fever, though), but reading the posts from this thread prompted me to find out if I had the green or the amber. It was after this check that I sampled the RP too, although color is not the issue I'm reporting here.
In checking out the GC color, I poured about 3 ounces into a 6 oz. clear plastic cup, the kind you buy to take on picnics. This particular cup is very smooth, very clear and without visual distortions when looking through it. I looked at the oil under flourescent lighting and in natural outdoor lighting. It was amber with a hint of green tint near the top. I assume I have the amber MO5 version even though it says "Made in Germany" on the oil container and even though there is a slight hint of green tint.
Anyway, I was impressed by how evenly the GC coated the inside of the glass. I could barely see a thin line which defined the edges of the pour path. I drained it all out as well as I could, and the coating was so evenly distributed that it was almost imperceptible without touching it.
I then took another plastic glass just like the first one and took some RP residue left in some qt. containers from my last oil change, turning the containers upside down and pouring the remains into the cup from the quart caps. I ended up with about two ozs. of the RP.
I swished the RP around in the glass to see if its coating was going to be as clear as the GC. It was close, but that isn't what got my attention. The RP left bare spots and formed rivulets in the area which received the swishing of the oil. I swished again, and it left bare spots and rivulets again, in different places this time in the "swished" area. The effect was almost like that created by a water swishing.
I checked the GC glass again. The oil I had poured into the glass I had poured back into the original quart container. I could barely see the edges of the pour path in the plastic glass, but ran a finger through the pour path, and the oil had left a definite coating none-the-less.
Who knows what kinds of coatings these two oils leave on the engine walls and parts at operating temperatures, but there sure was a significant difference in their respective coatings at 50 degrees F.
I wasn't sure I was going to use GC this winter because people keep saying it operates more like a 40W oil at operating temperatures. My car specs. call for a 5W-30 or 10W-30.
However, after having seen how the GC (even the amber version
) coats a surface so evenly and thoroughly, I'm going to hang onto it and run it this winter -- after I dump the RP at 3,000 miles -- regardless of the RP cost and despite how it makes my car feel.
Crazy? I don't think so, but then maybe I do have the Elven FLU -- Fever of Lube Uphoria (euphoria is spelled "uphoria" in Elven).