I have sorta tangentially commented on RP in my first thread, here:
Hi All,
Occasional lurker, first post here. Was planning on crashing
@Avery4 's excellent thread about the two VRP tests, because I don't have that much info to share to justify yet another thread, but well, maybe it's not polite to crash other people's threads.
Anyway. I'm an oil snob. There's no other word for it. I'm like that British gentleman who got stuck on a desert island and built three identical huts. When he was eventually found he was asked "
Why three huts ?", and he said "
Well, the first hut is my house. The second hut is my club. And the third hut - that one...
The short story is - I have fed two consecutive Hyundai 3.3 V6 engines on long wheel base Santa Fe models, a 2013 and a mostly identical 2017 one, exclusively on Royal Purple, from new.
While the 2013 was a lease which we returned at 38k miles, the 2017 was bought new and is driven to this day, at 127k+ now. So while I can say little about the 2013, I can talk about the 2017.
The car was fed exclusively - and I mean - ONLY on RP. For a number of reasons, the main one being that RP ended up on the short list of oil brands that I considered worth using when doing my research, that it was available at my local carwash (which is also an oil changing place with the same guys working there since I started visiting in 2013). The service is good, I've been watching them through the glass bay every time. So all in all, it is my go to place.
The RP I have always used is whatever RP full synthetic they have in stock (it's the only one in their full synthetic package). Possibly this one:
Although I don't remember seeing a Dexos 1 label on it. Then again, I haven't tracked every single label change throughout the years. Also, to be clear -
definitely not HPS.
Long story short - RP from new, 5k OCI. New York City daily driving till 80k-ish miles. More suburbia after that, but I still return to the same place for my oil changes.
The car has been going through about 1qt of oil / 1000 miles with clock-like precision, since 70k-ish miles (that I know of, that's when I noticed. Could have started earlier). My oil dipstick has always had varnish on it. Bottom of oil filler cap has always had varnish on it. By "always" I mean since I started paying real attention at the abovementioned 70k-ish.
I have to add that this engine's oil dipstick is not the best I've dealt with. It's smooth, non-serrated, and with the varnish on it reading levels is an exercise in self-control.
Anywhow - I have always given the oil the benefit of the doubt all that time. I got a Blackstone Labs analysis at 100k miles, which found nothing wrong and everything within specs.
But seeing the varnish disappear from the dipstick in about 500 miles after adding 1qt of VRP to the remaining 5qts of RP (see linked thread) after my last oil change, and seeing my car keeping the same oil level or almost during the last 1k miles (after having gradually gone through a total of about 4qts of VRP that were added 1qt at the time at 1000 miles intervals and diluted in the existing RP), I have to consider that this is the first time I see a positive difference, and that it is not thanks to RP.
So - not saying it's RP's fault that I got coked up rings (if that's what it was, not 100% sure yet), but if it was coked up rings indeed and it's not RP's fault - I don't know whose fault it was

.
Cheers.