Owner reviews for engine oil

I’ve moved to Castrol edge for my 9th gen.

Ultra premium is the best oil after amsoil, but amsoil is too expensive for this car, pennzoil is the best and cheap

Castrol edge and OEM filter for turbo.

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.

I was a diehard Mobil 1 Extended Protection guy, but fell into the hype about Valvoline Restore & Protect. Tried it on my 2015 Mazda6 2.5 with 95k miles and have to say I'm impressed. I bought it used, it was using about a quart every 3k maybe, and had some blowby. Otherwise ran good, had several 40+ mpg tanks. 

Switched to R&P, after 1k the blowby went away and after 3k it looks like it stopped burning oil.

After almost 2 weeks of usage, grabe as in grabeeee. napakasmooooth! hahaha tuwang tuwa ako kada throttle kasi mararamdaman mo talaga yung pagkatahimik+ smoothness + responsive throttle nya kaya ang laki ng tinipid sa gas. Kumbaga yung hinahanap ko na smoothnes ng takbo is dito ko nafeel when I start using this kind of oil. From 39 km/l naging 41.3 km/l na sya.

They sell Subaru branded Idemitsu at the parts counter

I’m personally a big fan of shell rotella. That’s what I’ve always ran and haven’t had any issues. My 05 STI is at 163k miles still running strong

I found Mobil 1 0W-40 to allow a lot more timing chain and lifter noise, especially at startup but even after, then switched to Castrol Edge 5W-40 and the noise suddenly wasn't there. I've used it ever since.

It is an oil from one of the lowest ranges of Castrol.

It is a 100% mineral oil, which is not good and therefore, in addition to greasing, cleaning and cooling less, it has a much shorter useful life, it needs more frequent changes, it is an oil how little/nothing is worth it for a motorcycle whatever it is.