Originally Posted by
PeterJ
Just to add to the knowledge base.
Did an fluid change on my D4, @106000 km, it had been previously changed at 49500 km so this oil has done about 57000km. Followed the Robbie's guide that is elsewhere in this thread, with no problems. My only deviation was that I replaced the fill plug finger tight while the oil heated to the 70 deg mark and I drained it a second time immediately after and repeated the process. For the final level check (post cool down) I added only 150ml. The oil came out quite black but no unusual odour compared to the new oil. The oil came out quite black after the first change at 49500 km as well, I have kept a sample of them all.
First drop resulted in 2900 g or about 3.6 L (or 3.42 L depending on the density value used, see below)
Second drop yielded 3627 g (I left it to drain overnight) which is 4.5 L (or 4.2L), so quite a difference so the next time I do it I will leave it to drain longer.
Out of interest and as a means of ensuring I know how much oil is coming out and going in I recorded the mass of all 9 x 1 litre bottles individually, also the mass of the empty bottle hence calculated the net mass of the oil for each bottle. The gross mass varied from 850 g to 900 g, the bottles from 78 g to 87 g (some of this variation can be attributed to additional
stickers and very small amounts of residual oil in the bottle) and so the net also varied from 768 g to 822 g.
One of the reasons I did this was to calculate the density of the oil, which I calculated to be 800g/L. I checked the MSDS for the oil and found it stated it to be 848kg/m^3, which is 848g/L.
On this basis of the MSDS quoted oil density not one of the bottles actually had a litre of oil in it. Quite a few did however if my calculated value is used.
I want to add that the measurements were taken using a digital kitchen scale, not a scientific NATA calibrated instrument so there are likely to be some errors. I did a cross check with another set of digital kitchen scales (different brand) and found they gave the same reading within 2g for 8 different objects so I concluded that they are not grossly in error. In the end, the important thing is to keep track of how much oil come out so that you can measure how much goes back in and avoid any underfill.
Peter