'Trust'

iTrader: (24)

I have 2 extra quarts of mobil 1 0w40, while im running mobil 1 5w30 in my car right now, its a lil low because of a leak, is it ok to mix the 2 or do i need to get 5 30?

Mr Incredible

It won't cause problems. Mobil synthetics are compatible with each other, and nowdays almost all synthetics are compatible with each other.

Research and learn about them to increase your knowledge base and comfort factor.

FirstYrLS1Z

iTrader: (4)

Yes,it is ok to mix the two.The 0w part is of lower viscosity than the 5w and will provide easier flow at start-up.The 40 part is of higher viscosity than the 30 part and will maintain viscosity and oil film better at operating temperature than the 30.A 0w40 has a HIGHER viscosity INDEX than the 5w30 and higher viscosity index is always preferred because of higher viscosity stability.

Flick5959

you only want to mix grades not brands

Weezzer

Wrong!

Patman

Mobil 1's 0w40 is their least stable oil viscosity wise. It thins out to a 30wt oil quite easily, while their thinner grades don't thin out hardly at all (but they begin too thin-so it's a good thing they don't thin out more! at least when their 0w40 does thin out, it's still a lot thicker than their 5w30/10w30 grades) Mobil 1's 5w40 is much more stable than their 0w40.