Give this a try on really dirty trucks.
I wash Limestone Dumptrucks, that work in the pit 85% of the time, these dudes get really nasty with lime mud. I have to get all the mud off, the underside of the bed, Steps, fuel tanks, frames, axles, and wheels.
Trust Me I've tried just about everything in the book,and I have found that my X-Jet works just as well as any thing in my nozzel box (zeros,rotery ect.).My X-Jet will take any amount of pressure, or heat that I can dish out to it, say 250deg.at 3500psi. and it don't wear it out.Don't get Me wrong a DK Rotory nozzel is a good tool to have,but when it comes to severe duty the X-Jet don't cost Me $45 to rebuild every few weeks.

------------------
Bill (CPS CLEANING and RESTORATION)
(740)819-2566