Engine oil Castrol or AMSOIL

I also wouldn’t run motorcraft period in my 5.0, in the words of a friend who’s a master mechanic “they sell cars not oil”. Just some food for thought, I did run it until he gave me this one line, I now run amsoil and my 5.0 and 6.2 and 3.0TT are all much quieter, for what ever that’s worth

Me running 5w50 Amsoil SSO full synthetic or 0w50 Eneos or 0w40 Amsoil SSO if being used in winter (down to -40F, and yes, I've driven these cars down to that cold)

Synthetic is better, always. Higher not viscosity has better shear protection. A good additive package that has great shear protection lets the housings wear slower.

Yes you can I’ve been using 10w40 castrol ever since I got it and I’ve been fine

This is the second time I had put Amsoil in my scooter and I had to post the findings over here for my fellow scooter riders here.

The performance jump is noticable, my access now pulls pretty graciously post 60 km/h before it was more noise and less acceleration with Castrol 5w40 synthetic. You can feel the acceleration in your bum and hands when you twist the throttle after 65 or 70 which is where most if the 125 cc scooters flat out due to lack of power.

Even doing top speed for more than 1 hour in highways you will feel no vibration thats how smooth the engine+Amsoil combo is.

The smoothness of this oil with this suzuki engine is next level my friend who borrowed my scooter for a day (apache rider) said it feels like riding an electric scooter that's how smooth it is. So do try!

I use Amsoil SS mainly because I do long drains, over 20k Km. So the price of the oil is not a big issue.

Great oil but worth it only if you do long drains.

I use Redline but for a million years I used Mobil 1 car oil. Before that we used Castrol 20/50 petroleum oil

I always ran castrol gold motorcycle 20w50 on my Harley's.

I always go for Castrol Edge. Always have, always will

I use the Castrol 10w50 that the dealer gives me for my 18 RS. I have clutch slip issues and it seems to keep it mostly under control vs Motul 7100 or 300V

AMSOIL - DO NOT USE THIS CRAP , No seriously this stuff is crap and it's not worth the risk. I put this in my R32 at 24,000 and the motor blew at 24,500 due to a depleted rod bearing.