too many variables involved, eg state of engine, trip lengths, etc.
In mine, I'm not comfortable going much past 15,000km, with the UOAs so far. I've gone 20,000km several times and it was OK, but 15,000 looks a little better for me.
Only real way to tell is used oil analysis, and for the average person, it's probably cheaper to use something like Delo 400 or Delvac MX and change every 5000km. I'm just partial to synths when turbo's are involved, particularly oil cooled only ones like the little Garrett on the 300Tdi and I flog the daylights out of my engine and it's had the fuelling upped, it's my work vehicle and needs to be reliable so I just use D1 and hang the expense.
The great thing with UOA is that you can pick up if somehing is astray, like a head gasket weeping. I just do one once a year now on all our vehicles. The other thing to remember is that one test is meaningless. A string of tests (at $35/test) needs to be done to establish a trend. All this adds up to $. Our vehicles do enough miles to justify the expense and we are getting it back on reduced oil and filter usage. The Patrol is five years old and just clicked over 225,000km. At one stage the missus was averaging over 60,000km a year, and an oil change every month under warranty was a pain.
I have a few UOA's to get done in a few weeks after I had a few weird ones a month or so back. I'm guessing it was BP's diesel fuel additive, but we won't know for sure till I re-test.
In the Patrol, we can easily exceed 20,000km and the oil has hardly broken into a sweat. It really looks like it could almost double that distance, but I'm in front financially (vs changing at 5,000km with dino) so out it goes. I'm guessing it's easier on the oil as
a) we now use ULSD here, so it desn't load up the oil with soot and sulfur which would tend to happen more with an indirect injected engine vs the direct injection in a 300Tdi.
b) it's a bigger engine so uses much less boost and doesn't get worked as hard.
c) bigger sump/oil capacity at 10.5 litres vs just under 7 for a 300Tdi
d)the missus drives it mostly and she's not as hard on the equipment![]()


Reply With Quote


Bookmarks