Engine oil OEM Mazda or Motorex

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).

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.

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.

It works great, maybe a bit expensive. I've run used oil analysis and change it 3-4k miles based on aluminum wear. I don't see a reason to use something else.

I use Motorex semi-synthetic 4t in all of my KTM's over the years in a 15w50 weight. It has never been an issue. I have used Motul 5100 and 7100 in other bikes before, and I prefer the 7100 over the 5100. It feels like the bikes perform better when the temps rise and I'm really riding them hard.

But then we replaced it with a SkyActiv Mazda3 that used 0w20 and proceeded to have a good long history with that motor that had 0 oil consumption in 125K miles; I did all of the oil changes myself and it was always 4.5qts in/4.5qts out every 5k miles.

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).

It takes a “synthetic blend” of motorex 15W50 oil. And uhh yeah works good I guess, don’t have to change it too often, and as far as performance goes, it doesn’t really matter because I’m on restricted power anyways so yeah ????‍♂️

Honestly Motorex is a good oil, but it is extremely expensive for what you get. I specialize in performing Used Oil Analysis (Worked for Reliability departments for mining outfits) and it’s just a Ho Hum oil.

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.