What oil are you using

[Number15]

I use Valvoline 8600es 15w40 or Kirkland 15w40 in my diesel truck, generator and tractor when it get's its change.
Castrol 0w40 in my P cars and my F150. I do UOA on all my high dollar equipment. 10-12k changes on the trucks, usually 5k on the cars.