When I started flying turbines 2 years ago I asked AMT USA what type KERO was it factory tested with, they told me the stuff out of the pump down at the local BP gas station. So I just buy my K1 at the local gas station for usually $1.50 gal. I have 50 gallons now thru my uat and MERCURY with a clean white filter.

I always leave the uat filled and capped off, even during winter storage, just my .02