Lets be honest, if it's just low on the dipstick IIRC it's about half a litre.
If you are planning on doing a full change soon, it's far better then having it low.
However, both should be 10w-40 so it is the correct grade, always best to have the same make oil but the long and short of it is it will be fine.
Just think about servicing it with a new filter (cheap enough with the forum ECP discount.

) soon.
