Engine oil Castrol or IDEMITSU

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

Last change I did was with Castrol Edge 0w-20 no issues.

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).

I've always run conventional Castrol 20/50 in my Gti's (past and current Turbo) without issue.

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

Castrol Edge 0W40 A3/B4 (European Formula), about 27$ per 5 quart jug at Walmart. Made in either Germany or Belgium. A real synthetic, Type-4 PAO based (no Type 3). Meets the strictest oil requirements from ze Germans.

12 Galant 2.4 always running Castrol edge 5w20 and oil filter change every 5k miles for like 60k miles now has 126k. Cars have never shut off or left me stranded or left any signs of hesitation.

Generally, brand matters a lot. Amsoil, Mobil 1, and Castrol are all great.

I run Castrol in my older cars and Mobil 1 in newer cars that I care more about.

I usually change the oil every 7500 miles and tend to use Castrol synthetic 0-40.

I just use German made Castrol Edge 0w40 (502 certified) oil. Ive used this oil since the car had its first oil change and it does not burn a drop and car runs great, i now have 59k miles and shes drives new as ever.