Spec’ing a fifth wheel is a no-brainer for a lot of new truck buyers: they take standard databook fare, letting the factory engineers decide based on gross vehicle weight and other information collected by the salesperson. Nothing wrong with that.

But wait. What about the difference between a cast and a fabricated top plate? Do you have a decision to make here?

The market is dominated by the cast-type from several manufacturers, led by Holland Hitch, along with Consolidated Metco and Jost, one of Europe’s biggest players. The sole proponent of the pressed-steel or fabricated fifth wheel is Fontaine, which invented the pressed-steel type to relieve a critical shortage of cast fifth wheels during World War II. However, Fontaine, too, announced plans to launch a cast fifth wheel.

In performance terms, the difference between cast and fabricated is hard to peg. The cast type may be slightly better at retaining lube, while the fabricated variant may be a touch lighter. In fact, if there are differences from one brand to another, they’ll be in areas like jaws or mounting systems rather than the top plate.

The issue of weight is “a crap shoot,” one expert told us. In the sense that within one brand’s offering you could weigh 20 fifth wheels of the same type and find differences due to variations in the welder’s art. The way the plate is mounted-inboard of the frame rails or outboard-will also add or subtract pounds, because an outboard mounting requires just a little more steel. Mounting systems and bracketry vary among OEMs, too, accounting for 50 or 70 pounds difference even when the same fifth wheel is being used.

But the bottom line here is that the plate itself is virtually irrelevant: the differences from one fifth wheel to another have much more to do with the active mechanical bits and how well they perform, how long they last, and how much maintenance they demand along the way.

And in those terms, while we can’t do enough research to help you decide, the differences can be significant. Talk to other fleet managers in your area and ask questions like “How often do you rebuild jaw mechanisms?” If they say, “Once a year,” the product they’re using may not be for you. Fact is, you can do better.