Engine oil Mobil or AMSOIL

I run 0W-40 Mobil 1 European that meets the spec on the bottle. 10k changes since new.

I personally run Amsoil and always have. I think they make a great product and their customer service is solid.

Ive owned four 5.7s starting in 2005.

Changed all of them with 5w20 full synthetic, no real allegiance to a brand, but always a major brand (Mobil1, Valvoline, etc); typically 5k - 7k miles  between changes .

2005 had 250k , burned no oil, died when it hit a tree

2006 had 240k, would use 1/2 qt over 5k miles after about 225k.

2013, traded in with 225k, burned no oil.

None of these ever had a valve cover off.  I purchased the 06 and 13 new.  The 2005 I purchased with 100k on it.

The 4th is a 2021 with 35k on it. So far, so good.

I've been running 5w30 Mobil 1 full synthetic on my 03 hemi. 238k miles and still running perfect with no tick.

Mobil 1 ESP has specs very close to Subaru Japans own Pleiades oils. Its got loads of great certs, is widely available, well priced and highly regarded by loads of people.

AMSoil signature series. Best stuff you can get!

I've used Mobil 1 in all my vehicles before this car. I have chosen Amsoil Signature Series for the WRX.

Go with whatever is easy for you to source and also meets the VW502.00 standard. I personally run Mobil 1 0w-40 or Liquimoly 5w-40, whichever I can get cheaper.

Suggested I change oil from Castrol Syntec to maybe Royal Purple or Amsoil.

I ran M-1 15w50 for 10k miles or so, and my car ran 10 degrees hotter on average than with any other oil I've used. Throttle response also felt sluggish.