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Kia Sportage 1.7crdi. - Mixing engine oil. - ronald bennett

Just done an oil change of my Kia Sportage 1.7 diesel. Capacity is 5.3 litres and i've put 5 litres of Castrol edge 5w30 C3 in so need a bit more. Probably get called a tight a**e but i've got half a litre of Castrol Magnatec 5w30 C3 left over from something else. Should be okay using it bearing in mind a litre bottle of Edge is nearly £13?

Kia Sportage 1.7crdi. - Mixing engine oil. - _

As long as the oil specification is the same, no problem.

Kia Sportage 1.7crdi. - Mixing engine oil. - edlithgow

I wouldn't personally worry much about doing this, but I wouldn't advise anyone to do it, because there is the possibility of unexpected interactions.

The cases I've heard of involve a change in extreme cold weather performance due to interactions between the viscosity modifiers, gelling the oil and damaging engines.

I mix oil (SAE40 1:1 with SAE 15W40 or SAE 20W50) as my standard fill, BUT

(a) The SAE 40 has no viscosity modifiers, so gotchas are even less likely.

(b) I don't encounter low temperatures in Taiwan

(c) My car isn't worth anything.

Specifications are unlikely to cover this. There is no way all possible combinations of oil have been tested in all conditions.

However, the fact that both your components are from the same manufacturer must mean the risk is very low.

Edited by edlithgow on 09/05/2022 at 01:08