Engine oil OEM Mazda or IDEMITSU

For [Naturally-Aspirated Skyactiv engines](https://en.wikipedia.org/wiki/SkyActiv), it is highly recommended that you use Mazda's own(Idemitsu) high molly GF-5 0w-20. [Arguably it is one of the best oil for skyactiv engines](http://www.cleanmpg.com/community/index.php?threads/45295/#post-357910).

Switch to Idemitsu ( Japanese oil ) - Manufacturers for genuine and even does factory fill for many, they are very premium oils with starting segment already beating the top shelf of alternative brands.

For [Naturally-Aspirated Skyactiv engines](https://en.wikipedia.org/wiki/SkyActiv), it is highly recommended that you use Mazda's own(Idemitsu) high molly GF-5 0w-20. [Arguably it is one of the best oil for skyactiv engines](http://www.cleanmpg.com/community/index.php?threads/45295/#post-357910).

Idemitsu 05-W30 from Unioil kasi I cant find Castrol for my Mazda

Mazda says every 7500 miles for normal duty OCI, and I’ve done every 7500 miles since brand new on my 2014 3z.

It’s now at 187k flawless miles, consumes no oil *at all* (I’ve literally never had to add oil beaten changes, ever, what goes in comes out every time), runs like new, seems easily headed to 250k.

Idemitsu is responsible for the oil that powered the Mazda 787b; they know the rotary like no other. I exclusively use their synthetic 20w50 and premix.

Regarding brands, if you want to stick with factory oil without dealer price, Idemitsu is the brand to get. I emailed Mazda corporate and they said Idemitsu is the OEM for their oil.

For Naturally-Aspirated Skyactiv engines, it is highly recommended that you use Mazda's own(Idemitsu) high molly GF-5 0w-20. Arguably it is one of the best oil for skyactiv engines.

So if you review the virgin oil analysis database, it includes idemitsu 0w-20 and 5w-30 and for both, the TBN is rather weak in comparison to other more readily available blends, also, the viscosity at 9.5 cSt for a 30w, some 20w come close to that. Does any of that matter? Not a whole lot, but it shows that there's nothing special about the oil. Generally speaking, higher TBN is better.

I encountered something similar when I took my CE Turbo in for service a few weeks ago. The invoice said 0W20 and when I asked the service manual why they used the wrong oil they told me “oh our technicians know what oil to use, ignore that.” Needless to say I have zero confidence that the correct oil was used.