Engine oil OEM Mazda or IDEMITSU

I bought a Mazda CX-5 dealer test car with 300 Km's on it back in 2015 when I moved up to Osaka. I drive a LOT and was getting the oil changed roughly every 5000 km's per Mazda's recommendation.

Idemitsu to both, because it’s designed and tested on rotaries.

I use idemitsu rotary 20w50

I stick to Idemitsu. I have a Sohn adapter fitted, so it's 10-30 Idemitsu in the engine, twice a year and Idemitsu Premix in the Sohn adapter and in the fuel tank.

I use Mazda's weight recommendation for my environment, as illustrated in your owners manual. I use 10W-30 and 15W-40 Full-Synthetic oils with zinc additives to stave off carbon deposits.

From my personal experience, I used to use Mobil 1 and Pennzoil Ultra Platinum oils, which are really high-quality oils. However, I did notice a big difference when I began using the OEM Mazda oil. I don't know what is so different about it, but my engine runs much more smoothly and very quietly. When I am at a stop light, I don't even feel the engine running, it's gotten that quiet, and I just hit over 100k miles.

I use Mazda Moly 0w-20 in our 2014 Skyactiv CX-5.

I don’t use the Mazda-branded version, but Idemitsu is my go-to oil in all of our Mazdas

Idemitsu is the only premix and engine oil I’ll use ... you can order it for a good price from TREx performance out of NJ and he will ship

For the record, this is NOT the exact replacement to Mazda 0W-20 GF-5 with Moly - Synthetic Engine Oil.

While this has high molybdenum, it's still a different formula from Mazda's own proprietary blend.