Engine oil Castrol or OEM Subaru

Yes you can I’ve been using 10w40 castrol ever since I got it and I’ve been fine

Oil being dark is a good indicator that you have to do an oil change. However, you shouldn't wait until it changes color to do it. Clear oil doesn't necessarily mean you can keep going.

It is well established that boxer engines want their oil changed and I do not think for a second that a visual inspection is valid for determining if it is time. Highly, **highly** recommend you change the oil per the manual without hesitation and regardless of what it looks like.

I use Redline but for a million years I used Mobil 1 car oil. Before that we used Castrol 20/50 petroleum oil

I always ran castrol gold motorcycle 20w50 on my Harley's.

I always go for Castrol Edge. Always have, always will

On my ( 2006 Mazda 3s 2.3l auto sedan 350k miles ) I don't burn a single drop of oil and the car runs great even the transmission and I've been sticking to 5W20 Castrol edge extended performance all year

My car is at \~7600 miles. I changed the oil at 500, 5000 and then I'll change it again at 10,000. I used Castrol Edge 5w30 for the first two and I'll use it for the third oil change as well. I'm going to send a sample of the oil at the 10k change to Blackstone Labs to see how the Castrol is doing.

I used Castrol oil and was not satisfied but this oil till date has helped alittle with consumption as well.

Castrol edge is junk.