Hi guys, need some advice on mixing oils.

1. Is it okay to mix different brand of engine oil with same viscosity. For example, 4L of brand A 0w20 + 0.5L balance of brand B 0w20 from previous oil change.

2. 0.5L balance of brand B 0w20 + 4L brand B 5w30.

I understand that different brand or different product range from same brand will differs in the oil blend. But will it have any serious impact to the engine? Since theoretically there will be some old oil remains in the engine during every drain and fill.

Reason is I don't want to waste the balance oil.

This post has been edited by Tokik Siwok: Dec 27 2024, 01:46 PM

thanks

Previously bought Liqui Moly Special Tec AA 0w20 during Shopee sale.
Moving forward I'm thinking to get something cheaper like Shell Helix Ultra if it is ok to mix oil.