I ran out of amsoil so i'm going with 0w30 German Castrol for winters and 5w40 for summer. Full synthetic.

 

I'm running Mobile one 5w-40

 

I'm using the Mobile 0-40w

 

I was running M1 0-40 over the summer as all Mobile's synthetics are on the thin side of thier weight ratings. I just did the first oil change on the new motor last weekend and put in M1 10-30 but will probablly swap back to the 0-40 come spring.

 

i use 5-20 with soild lifters i can,i don't need the oil to hold the lifters up.

 

I tried the Mobil1 5w-40 Truck and SUV formula for a little bit when I was experimenting with different viscosities and trying to see if any made a difference with my valvetrain noise/ticking...(it didn't make a difference with the noise, but my oil pressure when hot seemed to increase by about about 5 psi)