Engine oil Shell or Mannol

Ran Rotella T6 5w-40 in my stage 2+ (and beaten to hell) WRX right up to 120k miles when I sold it.

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).

Genuinely speaking, it's actually not bad oil at all. Apparently manufactured in Germany, meets or exceeds the OEM spec for my cars. In my 350Z which likes to drink oil, I change it using Fuchs Titan Race Pro S 5W-40 but I keep a bottle of this (also 5W-40) in the boot for top ups.

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

Rotella T6 5w-40

I run Mannol 5w30 for Japanese brands on my 202k km d16

Works fine but I might change to a slightly thicker one

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

Whatever full synthetic is on sale, last time it was Rotella T6 15w40, every 5k.

I run t6 15-40 in my 07 lbz with the cat oil filter adapter.