Changing and Topping up Engine Oil

[ceecee]

Can you top up an engine oil 5W-30 with a different grade say 0W-40 or should this be avoided?

I thought it might be ok if its a thinner grade or should it just not be done at all?

Cheers

ceecee

[SneakyNeil]

£50000 BMW - No

£500 ebay job - Yes

With a sliding scale inbetween

[EDLT]

I think 0w-40 is actually "thicker" (more viscous) when hot than 5w-30 it is only "thin" when cold.

[Xenocide]

http://pistonheads.com/gassing/topic.asp?h=0&t...

This is the thread you're after.