I read in the Erwin manual that there are 2 capacities for the oil in my engine (1.6tdi).

 

"Oil capacity with oil filter change" = 4.3 litre

"Max Oil capacity after engine repair" = 5.2 litre

 

Which means that for a normal oil change almost a litre of dirty oil is left in the engine. I'm only changing about 80% of it.

 

Which explains why, after draining a little under 4.5 litres from the engine doing an oil and filter change today, including cleaning out residual oil from the oil filter casing (replacement paper element-type filter) the new oil looks dirty almost immediately. Something I have never, ever seen on any engine before (the oil in my 95k mile MX5 stays so clean even after several thousand miles it's difficult to read the dipstick).

 

Which also means that except when brand new, the engine will never, ever run with clean oil. Which must shorten its lifetime, even with a 6 - 8k mile oil change. And it has a turbo whose oil requirements are so sensitive it can be destroyed in a few seconds (according to the documentation) if you rev the engine too soon after an oil change.

 

Why do I feel its not worth the bother trying to get the last bit of oil out of the sump?

 

Am I alone in thinking that an 80% oil change is daft.

 

Another "What fool thought that one up then?", or is it a case of "Is it me?"

 

 

 

I find it hard to believe that there is a litre of oil left in the engine after its all drained but I suppose the amount that gets retained in the head and in the pickup pipe and that is coated on all the parts it is possible.

 

And also, diesel oil always look black because of the diesel soot in the oil. This does not mean the oil is worn out and not doing its job. The oil is designed to keep the soot is suspension and judging by the mileage that get put on modern cars it seems to be pretty good at it.

 

Basically, don't overthink it, just continue to change the oil regular and you will be fine.

"Max Oil capacity after engine repair" = 5.2 litre

 

I would imagine this would be the capacity (total to the fill mark) of a dry engine.

 

Any diesels I've owned in just a few miles after a change the oil turned black. Most noteably on a BMW 6 cyl TD lump, it looked like it had never been changed, smelly horrible dirty thing that was but reliable.

Just changed the oil for the first time on our 1.6 TDi (2014) and I have drained off approx 5 ltrs (into empty 5 ltr container) so when topping it up I put about 4 1/2 ltrs in at first and allowed it to drain down and then topped it up going off the dipstick and there was just a small amount of new oil left in the container ! cheers Stuart

 

^^^ And it looked black within a few miles?

Did 2nd oil change last night, took out a little under 4.5litre (including getting every last drop out of the oil filter casing), which is what I put back in. After runinng for a few mins no, it didn't look clean and fresh any more. Probably washed down from the hollows in the cam casing or some such I would guess.