Quote Originally Posted by robed4 View Post
Read few articles on the net that it is safe to mix oil weights as long as both are of same category. So as not to waste
my in-stock TOP 1 5w/50 FS, I would like to mix it with a ZIC A+ 5w/30 FS with the following ratio:

1. For a 4L-oil capacity gas engine:

Top 1 : 2L
ZIC A+ : 2L

will result to Brand X 5w/40

2. For a 6L-oil capacity gas engine

Top 1 : 3L
Zic A+ : 3L

will also result to Brand X 5w/40

You thoughts please .......... thanks.

from : http://www.bobistheoilguy.com/motor-oil-106/

If while on the road you are forced to add oil there are rules. Let us say for example that our engine has synthetic Mobil One 0W-30. Use the same type and brand if you can. If you are using Mobil 1 then it is acceptable to mix different grades but use a close grade when possible. It is not a good idea to mix say 1/2 your oil tank with 0W-30 and 1/2 with 15W-50 Mobil 1. If there is no Mobil 1 available then use the mineral based Mobil oils next.

The last choice is to mix a synthetic of another brand. They should not react adversely if mixed but it may dilute additives. This is not a good combination. Use this combination if you must but only until an oil change can safely be performed some time soon.