Well, my input. I think Royal Purple is truly an awesome oil. As was said, it's a group IV oil with the synerlec being group V and I think they use a bit of group II for carrier purposes.
Anyhow, on the price. Like any other oil, just get it on sales like I do. Recently O'Reilly's had it on sale for a whole month for $39.99 with an awesome K&N filter. So that's around $5.99 a quart. Also, O'Reilly's sells the gallon jug of 15w40 year around for pretty cheap.... I think it's like $30 or maybe cheaper, I'd have to look again.
Also, you can do stuff like buy it on amazon. You could technically buy one of their 5 gallon pail's for $119.28 and that equals 20 quarts of oil for just $5.96 a quart. Free shipping, no tax. Or you could buy a gallon jug for $26.80 so that's four quarts for just $6.70 a quart. Again, free shipping, no tax. Or buy a 12 pack case for $86.49 which would be $7.25 a quart, free shipping, no tax.
Again, if you really want Royal Purple, it can be had for decent prices. It's one of the few remaining Group IV / V oil's still left out there, and if you compare the prices to other Group IV/V oils then you'd see, it's very competitive! In fact, compared to say Redline or Motul, it's downright cheap!
Also, to the above guy who said M1 10w30 HM is Group IV/V oil... how do you know this? Didn't Mobil 1 just come out and say they have been using their own custom Group III oil? I forget the silly name they called it, but I do remember this kind of blowing up here recently. Don't get me wrong, the end product is what matters and M1's HM oil's are absolutely great oils.
Anyhow, to the OP. If you want Royal Purple, I think you should go for it. They are a small American company who makes excellent high end products. Some of the best in fact. Their Synchromax is some of the best stuff I've ever seen for Manual transmissions that call for ATF. I've firsthand seen the difference, and not knocking Amsoil, but we first tried Amsoil's ATF and my friend seen the brochure for RP Synchromax and wanted to try it since it's made for just that purpose and we were both pretty blown away with the difference it made, even over Amsoil's ATF. Granted, that oil was not designed for that specific purpose like RP's was. But we were impressed.
Not to mention, RP's differential oil's are legendary. It's pretty much a consensus among many they make some of the best rear-end oil there is. Even people who don't use their oil oil will use RP in the rear.
I have some RP 0w40 I got on sale at O'Reilly's and it's going in my car tomorrow. It's a new oil they just came out with so I plan on giving my evaluation of it soon, and then doing a UOA on it just for grins to see how it holds up in my beastly oil shredder. But I plan on (very) soon getting some Royal Purple XPR 10w40 to run in my car as I bought a water-methanol injection kit and am installing it as soon as I get my throttle body spacer with methanol tap (only doing this as I don't want to drill any holes in my factory piping). But my point is, Royal Purple have specifically designed their XPR 10w40 and 5w20 specifically to handle running exotic fuels such as methanol, nitrous, alcohol, etc. It's what it's made for. Plus, that is a a Group V basestock oil and imo, the best oil on the planet, bar none. I can't wait to run it. But I won't lie, it's crazy expensive. For now, I'm content running the regular Royal Purple 0w40.
I have no prejudice for or against any oil. If you look at my post history or even my signature, you'd see I'me very fair to all oil's out there and have pretty much ran and tried them all. I have in my stash Amsoil, Pennzoil, Ultra, Platinum, Syntec, Edge, QS Ultimate, M1, M1 HM, M1 EP, SynPower, Royal Purple,GTX, Havoline, Motorcraft, MC5k and I forget the rest. I wait and catch them all on sale.
