Engine oil OEM Mazda or IDEMITSU

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).

I have a Sohn kit and run Idemitsu engine oil in the engine and Idemitsu premix in the Sohn. Runs lovely and smooth and the original cat is still doing the job.

We use Idemitsu for engine oil and transmission and red line for front and rear diff. Red line makes a good fluid for the transmission also.

2014 3, 0W-20 full synthetic (whatever major brand is cheapest) from brand new, every 7500 miles.

170k, runs like a top, burns not a single drop between changes, compression and fuel mileage exactly the same as new.

I use Idemitsu Wankel Racing Oil. 10w30, I think.

I use Mazdas 5w-30 Ultra DPF. Mazda once said that this was the oil that they're using, so I guess what's used by mazda can't be too bad for the rex

Idemitsu all day. It’s synthetic but what needs to be emphasized is the ingredient blend is purpose designed for a rotary to make the right lube + burn.

I've been running that exact oil in my rx8 for about 1k km now and its still as smooth as ever

Many reputable rotary shops have tested numerous oils over the years, and agreed that the bearings do not have adequate protection with 5w-20 or 5w-30, especially if you track the car or do any spirited driving regularly.