Engine oil MOTUL or AMSOIL

I keep using AMSoil after seeing a test results sheet from Blackstone (i think thats the labs name) for my 6.0. Tested after 15k miles and was better than 400 mile motorcraft.

Motul 5w-30 [or 5w-40 when ambient temp is above 80] 8100 X-clean EFE, based on IAG's recommendation for the FA20

I live in the same area with the same motor and run Motul 300V competition 5w40 on my high mileage track car at the recommendation of my mechanic

Amsoil Signature Series is all I have ever used, I will recommend it.

My preferred is Amsoil 10w30, the good stuff. Seem to burn less of it off when driving hard.

I would say 0w20 Motul 8100 is a solid choice.

I use Motul's 0w-20 "Eco-lite" and change about every 4-5 (or April-October really) with about 25 autocrosses and the highway driving to get to them.

I use Motul 300v 0w20, plus oil analysis from Blackstone Labs, currently every 6k miles until they tell me otherwise

I run Amsoil small engine oil in my 2000 inverter.

Amsoil since day one, never let me down and improves mileage as well.