Oil Top-Up

[Old_Geezer]

My woman's car burns/loses oil at random intervals. It has synthetic 5W-30 in it at present. She has a "bottle" of synthetic 0W-30 (same brand) in her garage. Is there a problem using the 0 to top up the 5 ?

[bhg481]

I have no worries about topping up oil with oil of a slightly different viscosity. Being lower viscosity oil you might find that you burn slightly more but not by a large amount. If you look in the car handbook they normally give quite a large range of viscosities which can be used.

[davebro]

I would use up the 0W-30 rather than throw it away & get the correct stuff in future.

[Old_Geezer]

Cheers. It was the mixing aspect that I was concerned about. Didn't want a reaction turning stuff to treacle or something.

[Old_Geezer]

I think the garage oil might have been bought for a previous car.

[retrocop]

//Didn't want a reaction turning stuff to treacle or something. //

No problems. You only really get that reaction if you mixed mineral oil with a vegetable oil like the old Castrol R which was basically Castor oil.That turned to treacle when mixed.

[Old_Geezer]

Thanks.
Think BA should go to the first response, my thanks too to those confirming and expanding on the info/understanding.