I have a 2006 Mini Cooper petrol engine, Can I top up with A3 engine oil if garage used C3 at oil change? The manual says usd ACEA A3, BMW LL 01 but the garage recommended topping up with ACEA C3 W-30. Very confusing!
Oils are miscible between each other. As long as both oils have a min and max temperature compatible with your car, you can mix then to top it up.
