Hi there, I've just completed an oil change on my 2007 E91 BMW with 4litres of Castrol Magnetec 0w30 which is rated at LL04. I want to know is it safe to top up with some Shell Helix 5w-40 which is rated BMW LL01? I would have thought so as it will be a max of 0.25 litres top up. Both are Fully synthetic.

Thanks, just to check.

Cheers,
P.