Hosing down undercarriage

I saw a Fluid Film test where best results came from no rinsing during the winter.

 

That sounds like what the Krown guys told me.

I got mine done in PA the last couple years. Same shops does a bunch of the central PA snow plows. Those guys get so much snow gunk built up under the trucks that they end up pressure washing them after each big snow. Apparently by the time they get back to Krown for a new coating, the underside is bare again. That’s why they suggest not washing the underside at all.

I’d say that goes for Krown or any other oily rust protection, including Fluid Film.

 

People will drive around on salty roads for weeks, then worry that spraying water under the truck will damage it.

 

I take mine through the touches automatic car wash once a month. Have the whole thing washed and rinsed including the bottom.