The Dexelia oil.Syntetic or not?
 

My car is lubed with Mazdas Dexelia 5W-30.
Is this a syntetic oil?
Its very expensive.Can I use other oils,fx the Castrol Softec5W-30?
If not,what oil do You recommend?
(My engine is a low output MT Euro,similar to US AT)

Dexelia is hydrocracked regular oil. The hydrocracking purifies and makes the oil molecules of consistent size. In the US, hydrocracked oil has been approved as being called synthetic as a result of a legal dispute over the matter between Castrol and Mobil. The US Castol Syntec 5W30 oil is hydrocracked. In the US there is a 0W30 Castrol Synthetic oil available that is made in Germany and is a true synthetic. It is referred to as Castrol GC or just GC on some oil
discussion websites.

But which oil is suitable for my car?
Here in Norway the Dexelia only comes in a bag with gloves and other accessories.One bag costs $45.I think that is too much and wants to change to another kind of oil when I change the next time.

If the Castrol Softec5W30 you mentioned is the same as the Castrol Syntec 5W30 available in the US, then that is a very good oil to use. It is not kind of the synthetic oil that Mazda has recommended against using.

I'll call my national dealer tomorrow and ask if it is tha same..
I'll come back here with an answer.

fyi- In the tech highlights CD it says "use non-synthetic oil only."

https://www.rx8club.com/series-i-tech-garage-22/tech-highlights-cd-57595/

Castrol.....
 

I think the premium Castrol sold in Norway is 'Castrol SLX LongTec', it is VERY good, and VERY synthetic! :D :D

S

The most premium Castrol sold in Norway is the TWS 10W-60.
I used to give that to my M3.
Will the longtec be good for my 8?