Was not sure how to put this in the title, but,
My A4 is a TDI2.0 Ultra Sport 150BHP
80,000 miles when bought
Now has 80,102m on clock and engine oil change due.
I do 4K miles a year max.
Using an electric pump to syphon out the oil (via the dipstick tube).
I believe the capacity is 4.7L; I sucked out about 4.4L. I then added about 4.5L of the Castrol. The system said "Oil Level OK" and was at Max. The engine probably had at most 300ml of used oil in - I guess.
All done with engine up to temp.
Next change in 365 days.
Question,
Does leaving that amount of used oil in the sump do any harm with the change for the mileage of the car and miles I do? Has it not been "diluted" by the new oil to some degree?
My A4 is a TDI2.0 Ultra Sport 150BHP
80,000 miles when bought
Now has 80,102m on clock and engine oil change due.
I do 4K miles a year max.
Using an electric pump to syphon out the oil (via the dipstick tube).
I believe the capacity is 4.7L; I sucked out about 4.4L. I then added about 4.5L of the Castrol. The system said "Oil Level OK" and was at Max. The engine probably had at most 300ml of used oil in - I guess.
All done with engine up to temp.
Next change in 365 days.
Question,
Does leaving that amount of used oil in the sump do any harm with the change for the mileage of the car and miles I do? Has it not been "diluted" by the new oil to some degree?