Engine oil Shell or AMSOIL

It's perfectly fine for the WRX, and it's what I use in mine, as well as its two previous owners. My car's maintenance records include two reports from Blackstone Labs detailing their examination of the Rotella T6 5W-40 oil and according to those the engine has worn very well on that oil

I personally swapped from 5w-30 in my OBXT to T6 5w-40 and have noticed a decrease in oil consumption (newish engine with 28k so that also helps).

If you only daily and don't run hot, hard, or do lots of WOTs; then just use Honda or other quality oil that you are comfortable with. If you push it harder and want to spend money, use something better like Amsoil Signature (my choice), Royal Purple, or Motul.

I run Amsoil signature blend and filters. Expensive but I believe in it.

I only use amsoil in my gti...would never use n e thing else in my car

I’ve personally ran amsoil in all of my vehicles, and haven’t been disappointed

I run Rotella T6 5-40 on my VR6 and also an 850 Turbo.

Rotella T6 5w-40

Ran fine when I got it but I switched to amsoil and it has changed the sound of cold starts. MUCH QUIETER!! and seems to have smoothed out the idle over time.

For instance, i use 5w40 she'll helix ultra, and it is thin 5w40 and it has ll01.