Understanding Carrier Capacity – It Is More Than Just the Deck Rating

By Brian J. Riker

Picking the right truck for your fleet can be confusing, no doubt about it, especially when you have a smaller fleet and are trying to find the perfect balance between enough truck and the right purchase price. It is important to keep in mind that not all trucks are created equal, and numbers never lie – except when they do!

When selecting a carrier, aka a rollback or flatbed, there are several key things to consider before laying down your hard-earned money.

The first consideration is what does your current mix of work include, meaning do you do mostly motor club towing with a little police crash work or are you looking to haul two cars all day long for the salvage auction? How about hauling forklifts or other construction equipment? Each use case has specific requirements for selecting the right combination of chassis and carrier deck.

Perhaps the two most common carrier configurations are the 20 to 22 foot deck, either steel or aluminum, mounted on a class 5 or 6 truck chassis. These would be your no CDL required light duty carriers, typically a Ford F-550 or Ram 5500 (class 5) or a Freightliner, International or similar truck (class 6). The carrier decks mounted on these chassis typically have a 6 ton (12,000 pound) rating and can be equipped with a wheel lift for hauling two vehicles at the same time.

The limiting factor with these configurations is almost always the chassis, not the carrier deck or wheel lift. This is because the payload capacity of the truck is determined by the gross vehicle weight rating (GVWR) of the truck chassis minus the tare (empty) weight of the completed truck with the driver, fuel and typical tools or other equipment needed to complete the job assignments. The payload capacity of a class 5 or 6 truck is much less than the rated capacity of the carrier deck installed upon the truck chassis.

A typical class 5 truck, which would have a GVWR between 16,001 – 19,500 pounds, with the most common being the 450/4500 series trucks at 18,000 and the 550/5500 series at 19,500 pounds, will have a tare weight around 13-14,000 pounds. This only leaves 4,000 to 5,500 pounds, at best, for supporting the weight of the vehicles or equipment you are loading onto the deck and/or wheel lift for towing or transport. This is much lower than the deck capacity of 12,000 pounds!

The same can be said about the typical class 6 truck, which most often has a GVWR of 26,000 pounds to stay just below the threshold of requiring a CDL. These trucks, when properly built and equipped, will have an average tare weight of 17,000 pounds, give or take a little based up having an aluminum deck, fuel tank size, engine size and other considerations.  With a GVWR of 26,000 and a tare of 17,000 there is only 9,000 pounds left for payload, and that is under ideal weight distribution and loading circumstances.

These payload capacities, which are the lesser of the GVWR minus actual weight or the rating of the carrier deck/wheel lift, can be quickly exceeded, sometimes with just one vehicle, and often when hauling two vehicles at a time or trying to transport a forklift or other construction machinery. This is why it is critical to understand what expectations you have for your truck when purchasing it, and why educating your drivers and dispatchers as to the limitations of their truck is critical to not only the longevity of the truck but also the safety of the motoring public.

It is never safe or acceptable to exceed the GVWR of the truck under any circumstances. Just because something physically fits on the deck doesn’t mean it is safe to go down the road, even just a “short” distance. Not only are you taking a risk of sudden failure of the truck’s suspension, tires, wheels or other components, including the capacity of the braking system, whenever your actual weight exceeds 26,000 pounds you jump from non-CDL right into requiring a CDL to drive the truck, opening yourself up to additional violations and liability.

One more word of caution when selecting the right truck for your workload. Not all “big” trucks are created alike, even though they look similar. A prime example of this is the Freightliner M2, which usually is a class 6 truck with a GVWR of 26,000 pounds, but not always. There is a class 5 version of the Freightliner M2 with a GVWR of only 19,500 pounds which results in a really low payload capacity since this chassis, when built as a carrier, will still have a tare weight near 17,000 pounds. This will leave you with just 2,500 pounds of payload capacity, making nearly everything you haul overweight, illegal and unsafe!

Please pay close attention to the GVWR and actual weight of your trucks when deciding which trucks are the right fit for your fleet. Always check the GVWR label inside the driver side door jamb and, as a best practice, get a scale ticket for each truck after you have outfitted it with tools, equipment and a driver so that you can make exact calculations for each unit in your fleet.