This is my daily, has 179k miles. gets about 80% city and 20% highway miles. I drive it hard. I've always done 10k oil changes with
pennzoil platinum or ultra platinum looks like I have been using plat high milage - just whichever I grabbed bc they look similar. I keep up with all maintenance and overall I've not had any issues. No oil burning or anything to note. valve covers are starting to seep so I may get to look underneath and see how the levels of varnish or sludge are when I do decide to replace them. Recently I've been working on my other car (2002 avalon) at trying to clean up some sludge and varnish on it with hpl and frequent oil changes so I decided at this point in its life the xterra may benefit from some 5k oil changes. Thus why I sent this UOA for the 4400 mile oil.
main concern is why that TBN is so low after only 4400 miles and that I still think iron/lead/tin are higher than I would like. I know its only 2 UOAs so not much to see trend wise and on the 4400 mile UOA the wear metals are about half which makes sense for the oil interval being half as long. overall though what do you all think?
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