Z4-forum.com

So I've seen loads of similar posts about engine oil but nothing that quite answers my questions. Basically the amber oil light came on as i switched my z4 off today and after checking the level on the dashboard it looks like I've hit the low oil point and suggested to top up 1l. I would do an oil change but don't really have the tools available right now so for now am just planning to top up a litre.

My question is, is there going to be an issue with mixing of different viscosity oils? I don't know what was last put in this car but at the moment i am edging towards putting in some 5W30 as seems fairly standard. I've also noticed theres a difference between LL01 and LL04, any issue with these two mixing? Also any suggestion of brand?

Cheers, Barny

Adding / mixing brands or even viscosity is unlikely to do any harm until full change is due .
Ive long been a fan of Millers oils & rarely have i ever had to top any car once its been changed .
https://www.ebay.co.uk/itm/Millers-Oils ... Swn-lZcxDa

Hi Barny,

I don't think mixing a small amount of oil will do any harm but you currently have Castrol Edge 5W30. Supplied by myself and changed by BMW for the stamp! Hope all is going well with the car. I miss her a lot!

Cheers,
Simon

Thanks guys. Have heard good things about Millers so will consider for future full changes.

Simon, really useful to know whats already in there so thanks. Will likely go for the same. All good with the car, a very impractical daily driver but definitely enjoyable!

Barny

Most oil manufacturers will say you can mix viscosities with no issues. Heck most even say you can even mix conventional and synthetic with no side effects.