Obviously its best to top up using the same brand and grade of engine oil, however, as long as you top up using the same grade is it critical if you mix the brands? Off to Spain in 2 weeks and noticed the oil level little low in my M696. I have fully synthetic 10/40 Shell in at the moment but have a brand new litre of same grade Fuchs in the cupboard and don't really want to buy a litre of Shell to use half a cupful.
As long as it's the same grade and type (synthetic, semi-synthetic etc) I would have thought you'll be OK.
Oil is oil, doesnt make any difference as long as its the same grade and type, just like Robarano states :smile:
As an engineer I know oil companies spend millions and millions on oil development to the extent that baring viscosity and type (mineral/semi/fully synthetic) oils can be very different from manufacturer to manufacturer. There is a chance of upsetting the balance of additives that are added to the oil. Now putting it in a 1970's DAF I'd have no problem with. But my bike... my own personal pride and joy, I'd drop the lot and fill up with a specific brand. Again, if I was employed in a bike garage then I'd probably go ahead and do it. You should be fine. How long ago was the last oil change anyway?
