Getting The Right Truck

From the engine to the body's overhang, all components should be sized to your application.

ED THOMAS
CONTRIBUTING EDITOR

      Out shopping for a new truck? Whether you buy new or used, certain principal points need to be kept in mind or you risk owning a truck that will be too much or too little for the job. This is especially true among medium-duty, where size and cargo-carrying abilities vary considerably among the industry's weight classes.
      The ideal truck will be built just for you and your job. But the reality is that, as close to your hauling application as it may be, certain compromises are involved. For instance, the engine may be over- or underpowered by a little or a lot, yet get the job done every day. And something in the cab may not quite suit your driver, but he'll get over it — you hope.
      The main things to avoid — aside from getting a lemon or a make of poor quality — is a truck that's way too large or somewhat too small for the job. If it's too big, with a powertrain, wheelbase and chassis components grossly oversized for what they need to do, you'll probably pay more in price and operating costs. And the truck will be more to handle for the driver than it's worth. If everything's too small, you may save some upfront costs but won't be able to carry as much as you want, or at least not for long, as it'll be overburdened and break down early and often.
      Everything in the truck-buying process starts with your hauling job. How much in weight or "cube" must you carry, and where? Who'll drive the truck? And how long will you keep it? You must have the correctly sized body in mind, because the chassis must be long and strong enough to tote that body, and to properly distribute weight between (or among) the axles. If you're buying used, you can probably find many trucks on dealers' lots — ones that were built for your kind of hauling — that will work. Still, it's good to check some basics, like...
      • Gross vehicle weight rating — GVWR is declared by the truck's builder, and appears on an ID plate somewhere in the cab or perhaps on the firewall. GVWR is the sum of the weights of the chassis, body, all anticipated equipment, plus the payload. Payload capacity, in turn, is determined by the strength of the frame, suspensions, axles, and wheel-tire assemblies. But of course payload plus chassis/body weight must not exceed the vehicle's GVWR.
      Honestly and accurately determine all those weights in your operation, add them up, then go shopping for a truck. Tell any sales person or seller what GVWR you think you'll need. It may be okay to buy a truck with more weight-carrying capacity than you need, but never buy one that's rated for less than your anticipated full gross weight.
      If your driver doesn't have a commercial driver's license and you don't want to get him qualified for it, then you should buy a truck with a GVWR of 26,000 pounds or less. Over 26,000 pounds is the legal threshold for requiring a CDL. (Another factor is the hauling of hazardous materials; anyone doing that also needs a CDL.)
      • Powertrain — Diesel or gasoline, and automatic or manual transmission are your two main questions. Diesels are taking over the medium-duty markets, as they did many years ago in heavy trucks, because they are usually durable and stingy on fuel. There's still a place for gasoline engines, but only one domestic builder (and its import affiliate) still offers them. Arguments for gas include consumer use (meaning rental trucks), low mileage (20,000 or less per year) and the need to burn alternative fuels like propane.
      Any horsepower rating is often "enough" for a non-driving owner, and never enough for any driver. But remember that a truck, especially one with a tall van body, must push air as well as carry the load. If you're inclined to be stingy with horsepower — or even if you're generous — add aerodynamic enhancers to the front of that truck body or to the cab's roof. A good aero-aid begins helping above 35 or 40 mph. It'll ease the work of the engine, let the truck cruise at a reasonable speed, and save you money in fuel.
      • CA dimension: The right chassis will have enough frame space on which to mount the body. The space is called cab-to-axle, or CA, which is the distance from the cab's rear wall to the center of the drive axle (or from the cab to the center of the tandem, or CT). Sometimes exhaust or air-intake stacks behind the cab reduce that space, so "effective CA," which begins just behind that equipment, becomes the working figure.
      • Wheelbase — The longer or shorter the wheelbase, the greater or lesser the CA. Of course, cab style (cabover or conventional) also comes into play. Generally, a cabover needs a shorter wheelbase and shorter overall length to mount the same body that might otherwise go on a conventional. This helps make cabovers so maneuverable and useful in tight urban quarters. Conventionals have gotten more compact in recent years, and have other advantages — comfort and perceived collision safety, for instance — so still account for 80 to 90% of sales, depending on weight class.
      If you intend to buy a cab-and-chassis unit, first have in mind the type and length of the body that will go on it. If you've found a real bargain in a cab-and-chassis truck, whether new or used, remember that it won't be a bargain if it isn't right for your body. The CA of the chassis will be a varying amount of the body's length, with more or less overhang behind the axle allowable for varying types of bodies. For a 24-foot high-cube van, six feet of overhang might be okay; but for a dump truck, only a foot or two is allowable.
      • Brakes — Air brakes are optional on many Class 6 and 7 trucks, and are favored by buyers of trucks with GVWRs of 28,000 pounds and up, but sometimes down to 24,000 or so. This is because an air brake system's foundation brakes (the actual stopping apparatus, usually consisting of drums and shoes) are beefy in size, and can absorb a lot of heat. That means they last a long time before replacement. And replacement shoes and other parts are common items, available at many parts shops as well as truck dealers, and at low prices.
      Hydraulic brakes generally have fewer square inches of lining material per pound of truck, so can wear out faster. And the parts are often proprietary to the truck builder, so must be bought from the dealer at relatively high prices. However, engineers have improved hydraulic braking systems through the '90s; many systems now have high-performance discs at all four wheels, and on many trucks hydraulic systems are approved right up to 32,000 or 33,000 pounds. If your truck does not need a compressed air system to run anything else, today's hydraulic brake systems are probably more than adequate.
      • Tires and wheels — Try to get tires that are right for your application and wheels that are easy to maintain. Trucks today come standard with radial tires, but you may want to try to specify "urban" radials if yours is an entirely city operation where tires must bounce over curbs and combat potholes. A highway tire is better if your truck spends a lot of time on freeways. Wheels today are almost always steel discs, though you might want aluminum discs for light weight or appearance. Older used trucks might have spoked wheels, which may run on "split rims for bias-ply tires. If you buy an "oldie but goodie" truck for limited use, be prepared to put up with higher maintenance and limited availability of parts, not just for wheels and tires but many other items.
      You can spend as much or as little time as you want in buying a midrange truck. Managers of big leasing fleets, for instance, develop specs as part of their jobs, and you might take some cues from them — or even buy their used trucks, if they're right for your hauling task. If you've got another business to run and can't afford to make truck specs a career, either buy the type of truck that successfully hauls what you do, or work with honest dealers so you'll get what's right for the job.