Engine oil Mobil or Castrol

Absolutely always use mazda filter and the owners manual says use Castrol which the three local Mazda dealers use this I also go with it. Over 60k miles with oil changes anywhere between 3k-6k and still runs great.

I once used the 20k mile oil, but changed it at 12k; my engine seemed to run nore smoothly, after that. I swore off longer oil change intervals and went back to regular Mobil 1.

It is good oil! The only recommendation for C5 Corvette's and other cars.

I use Castrol GTX 20W-50, same as what the manual calls for. I know the oils changed since then but the previous owner didn't care for the car properly so I feel like the detergents are necessary.

Everything I've found for my 2008 Rabbit 2.5L engine specifies Euro 5W/40. Although you can find it in several brands, the best price I've found is the Castrol Edge Euro 5W/40 at Walmart for the 5-quart jug.

I've used it, no problems

Yes that's what I've been using for my 2020 hybrid.

Mobil 1 0w-30 AFE has the correct certification, I just used that. Easy to find.

FWIW: I live in Maryland and use Castrol Syntec 5w-40 in my 2012 JSW 2.5. I usually buy the filter and plug/washer from the dealer because they have the best price and I don't have to wait or pay for shipping.

I put mine in around 20k. The first change I did - it had 2 small metal shavings. I got very nervous. Ever since then there has been the powder you have in the pic above. Sometimes more sometimes less. The 2 times I have used Castrol I found more than other times (This could mean it protects less or that it carries the particles better than other oils). I will only become worried when I start seeing shavings. To me it's only an additional monitoring system. Like in a tranny - powder is ok, but shavings mean save up some cash. oh and my car is now at 125k.