Last name: Kiefer. This interesting and unusual surname is of Germanic origin, and is a metonymic occupational name for a maker or repairer of wooden vessels such as barrels, tubs, casks and vats. The derivation is from the German kief(e), kufe, itself coming from the Old High German kuofa, barrel.
Commercial Driver's License (CDL) A CDL is required to drive any of the following vehicles: Any combination of vehicles with a gross combined weight rating (GCWR) of 26,001 or more pounds, providing the gross vehicle weight rating (GVWR) of the vehicle being towed is in excess of 10,000 pounds.
You will have to again check with WA, but here in CA you are still required to keep a log book and posses a valid medical card even if you juts have a class C but are driving any commercial vehicle over 10K GVW even though you do not need a CDL. And if the actual truck weight is 18K...I would register it as 26K, that way anyone can still drive it and you have a few thousand pounds of payload capacity should you want to toss anything on the truck or pull a trailer.