Royal Purple in my Tranny

[Joe_Black]

No worries Tone! I know the hype keeps getting better and better from these wanna-be's, but the proof is in the field. When they show up being used by people whose lives are on the line and the longevity of the equipment makes the corporation's bottom line, then I'll take a second look. I know they'll be there one day, but that isn't today and I personally can't afford to take a chance when there's a clear-cut leader. Each and every Isuzu and other vehicle I've owned since 1986 has gotten 100% Mobil-1 and all the Isuzus (a total of 7 so far) have given me well beyond 150,000 miles of trouble-free service, with the exception of the Dragon currently at 30K and the IronMan at 115K. So that's my experience first-hand, and I share what I've learned from other proven sources. I'm not saying Royal Purple or other "synthetics" are bad, just that there are better choices with one heckuva lead in the industry. And that lead is what will make others try harder to make an even better product to garner greater market share. That's what innovation and business is all about, and we as consumers ultimately benefit from it. So remember, as the market isn't regulated at all, they can say they use the same base stocks and have super wonderful additives all day long. That's hype. When some guy working sub-zero weather on a piece of million-dollar equipment that's running shifts 24 hours a day starts using it, then that gets my attention.

[mbeach]

I used Royal Purple oils for a couple of years.
I switched over from Redline and Neo synthetics for a few reasons. One was price/availability, also Redline was specifically mentioned to be damaging to the center diff of the Subaru AWD system.
The Royal Purple did a great job of quieting a noisy gearbox and keeping my LSDs in working order (actually I think that it tightened them up a bit).
In the engine, it seemed that there was no difference whatsoever between my old Mobil 1 and the new Royal Purple. So I used the purple in the gearbox(es) and Mobile 1 in the engine. It's easier to pick up a quart of Mobil 1 than it is to find a quart of RP/Neo/Redline when you're running low.

A few weeks ago, following a service tech's advice, I changed the engine oil over to Mobil 1 (0W30). I've put on @1000 miles since then. My engine is quieter now, and runs a little cooler. Most importantly, my fuel economy has improved dramatically. My last tank (@85-90% highway at 70+mph) worked out to an astounding 18.7 mpg.

Royal Purple is good stuff, but for the sake of cost/availability/recent performance I'm going fully over to Mobil 1.