Engine oil Castrol or OEM Mazda

I've always run Castrol with no issues. The biggest thing is to make sure that whatever oil you use meets the spec required by your engine.

I use Castrol GTX full-synthetic 10W-40, as I live in Texas where the average temperature is hotter than the rest of the US and oil weather varies drastically. During the summer, I've considered bumping up to 15w-40 due to how hot my startup temps are on a "cold start".

I put castrol, engine sounds better to my liking, anyway make sure to check the user manual for the EXACT OIL CAPACITY AND TYPE

I’ve always used castrol edge on my old cars, and the oil comes out cleaner every time I do an oil change. That’s been my experience

High mileage oils like Castrol edge have more detergents than other oils, not a marketing gimmick.

Change my e90 n52 every 15k, castrol titanium 10w-40. blackstone reports confirm the oil still meets spec with plenty of detergents left. Showing no signs of wear at 170k.

I just run castrol edge on mine. No issues.

I myself use Castrol Edge (in 0W20) for my GJ. But I add a bottle of Lubro Moly MoS2, for that added molybdenum (mimics OEM moly infused Mazda 0W20).

Been running Euro blend Castrol a few years and happy with it. Engine is getting close to 200k, modified, driven aggressively. I'm sticking with works for me.

have used Castrol 5w-40 as VW calls for and change at 5000 mile intervals. Now at 129K, it still uses one or two quarts between changes and performs as well or better than new.