My latest UOA is attached. Wear metals all look great, iron is down, but it was a shorter interval this time (7k, vs 10k last time). TBN was a bit lower despite fewer miles, but the oil was also in the sump for 21 months on the 7kmi, vs 15 months over 10kmi, and the longer time may have dropped the TBN despite the lower miles.
Both of these oil changes were using Castrol oil that I purchased in bulk from the local Land Rover dealership; they pumped out of their 55 gallon drum into my gallon jugs. This was also the last time I was able to source 5W-20 from the dealer, they only carry 0W-20 now, which I wasn't interested in.
So, the LR4 now has Red Line 5W-20 in the sump. I may change it early just to get an idea of what the numbers look like (i.e., change at 4kmi instead of 7kmi). The additive package is probably very different in the Red Line but I'll find out details in the next analysis. I'm expecting higher levels of ZDDP and moly, but perhaps a bit less calcium. As long as the wear metals remain low and TBN is north of 1.0 I'll be a happy camper.
Side note: Oil consumption appears to be zero on the electronic dipstick, but I am measuring 1 quart less drained out than I had put in. Also, there were a dozen or two dragstrip runs this spring.
