Engine oil OEM Mazda or IDEMITSU

The oil was Idemitsu Synthetic 0W-20 with 12.5k miles on it. Once again, trace metals and flashpoint were within normal range. I also ordered a TBN to measure the amount of additive left and that showed there was still plenty of active additive remaining.

In terms of oiling, get a sohn adapter so your apex seals aren't being lubricated with crankcase oil, and instead are injected with rotary-specific oil, like idemitsu.

Remember that the rotary engine burns oil by design and does not particularly like eating synthetics. Expect to use old fashioned dino juice and change your oil every 3000 miles.

Although this is exact replacent, mazda OE still uses Mazda branded GF-5 which is exactly the same oil but branded Mazda....

Love these high molly low viscosity oils. Absolutely the best out there

Subaru OEM oil is Idemitsu 0W-20. I currently use Idemitsu Zepro\* 0W-20, a high-moly formulation from the same manufacturer.

That's the wrong oil. You want the Idemitsu eco gold medalist advanced moly 0w-20, which is basically the same as Mazda oil(Idemitsu makes the mazda oil).

Idemitsu zepro eco medalist advanced moly 0w-20. Basically the same thing as Mazda's oil.

You don't need to add any more additives to modern day oils. You said you will be using Mazda 0W-20 oil? This is one of the best 0W-20 oils on the market. It is made by Idemitsu for Mazda. It has very high Viscosity Index of 221. Most 0W-20 oils are around 170. This means it is one of the lightest 0W-20 at start up. This is what you want in the winter.

They should be using 0W20 full synthetic oil (not synblend crap). Its not going to hurt running the 5W20 in it instead but next time mention it at write up. Mazda claims benefits such as better cold start protection and better efficiency among other things.