I run RL almost exclusively (see sig), and I have found that when switchingfrom a ddifferent oil, what works best for me is to start with a low mile OCI, and increase incrementally (ie 1k, then 2k, then 3.5k, then 5k). It is the most powerful sludge removal agent I've seen in action, but as a result you will see the characteristic black oil color combined with quick TBN drop for the amount of time it takes to get "established" in your motor.
I have found that with continuous use, the TBN drop slows greatly, and I run 5-7.5k miles and could likely do 10k before having to really think about it.
It's also been a very sheer stable oil in my experience, so don't get a higher grade expecting it to drop, it won't. I run 0-5w40 and it's never once tested even on the border of either viscosity extreme.
If you are willing to spend the money, it's one of the absolute best oils, period. I can't think of any other oil that I can put in any of my cars, drive 2k on the street, head to the track and put 1k miles of HARD use over a few days, and then drive another few k on the street before changing, and do all this without a single issue.
Even better, I have lower oil temps w RL than I've seen w any other oil, period, by 10-30F on track.
And as mentioned by clevy, their gear oil is really top notch stuff.
