Oil mixing.

[martin j.]

Daughter has our old Leon diesel and it uses a little oil, topped it up to the mark before we went off to mot but that was the last top up I have, but in the garage are two 1 litres of long life Castrol oil suitable for 507.00 requirements, so, can I mix this LL oil and standard as and when required? Ta.

Oh, while I’m asking, the dipstick in this engine has the stupid black plastic knobbly end that makes it awkward to easily see the level, so is there maybe another dipstick from the vw/audi range that is the simple bent metal type that I could use. 2.0l tdi PD Engine btw. Ta.

 

[RUM4MO]

I'd expect that Longlife oil is okay to add to what is in there already, which I assume is fixed time/miles oil, and you are intending to replace the oil every 10K miles or 12 months.

Dip sticks, I'd say none are much better than the other, makes a simple job slightly challenging, I remember when friends of ours got their first new Leon MK2 as soon as it was launched, and the husband was not impressed, that was also probably a 2.0TDI PD, that was their sample of VW Group cars, so far they have had 3 in total.

 

[The Daily Meme]

Synthetic oils these days are formed of a base oil which is a relatively thin oil, and an additive mixture which contains corrosion inhibitors, emulsifiers, anti foaming agents and pH moderators.

Adding a different oil to one already in the car won't have any serious adverse affects. The only difference between the oil you added and the one in the car will likely be the base oil and the composition of the compounds used to acheive teh above effects.

I used to work for Lubrizol and they produce the additive pack for Castrol and most factory fill fluids. I tested most, if not all new fluids that were sent to OEM's or manufacturers like Castrol for these exact problems. You may even find that they could well be the same additive pack.

The worst case scenario of you mixing two different engine oils is that one of the additives may cause some of the compounds from either one of the two mixing oils to drop out of solution which would cause the oil to cloud a little but if your engine runs regularly enough. The sheering produced during general running about will mix anything back in.