Choosing basic truck specs

One the main distinctions to keep in mind when choosing a dump truck is whether you want a truck primarily for off-road or on-road use. The differences between so-called "vocational" trucks and highway trucks affect engines, transmissions, frames, and more.

Exactly what you'll be hauling is another key data point for the dealer. Dump trucks for hauling demolition debris have quite different requirements than those that will be used in landscaping applications.

What specs do you need?
In the long run, you want a truck that will give the best return on investment. But you have to consider more than just the initial purchase price: make sure you include all of these factors in your decision:

• Up-front cost
• Load capabilities
• Maintenance costs
• Resale value
• Fuel costs

Keeping those factors in mind, you'll have to decide on several key specs for your truck:

• Power – Heavy-duty dump truck engines typically range from 270 to 500 horsepower. Don't choose on HP alone, though: low-end torque is essential for moving full loads. Work with your dealer to select the right match of horsepower, torque, and gear ratio for the loads you plan to haul and the type of driving you’ll be doing.
• Axle ratings – Heavy duty dump trucks often have higher axle ratings than other types of trucks, often 18,000 to 20,000 lbs for the front axles and 40,000 lbs or more for the rear. Smaller heavy-duty and most medium-duty trucks are more commonly rated at 10,000 to 16,000 lbs front and 20,000 to 30,000 lbs rear.
• Transmission – Overdrive magazine recommends that dump truck buyers consider Allison automatic transmissions, as they're better suited to the frequent stops and rough use a dump truck gets. On the other hand, traditional 8- to 18- speed manual transmissions give you finer control.
• Body length and type. Dump truck bodies can range from 8' to 20' or more. Common sizes on medium-duty trucks are 9' to 12', and heavy-duty trucks are often in the 16' to 18' range. The exact type of material you're hauling will help determine the style of body you need – elliptical or half-round dump bodies help dump loose materials, while square boxes offer more total capacity in the same length.

Some additional specs to consider:

• Number of axles – While smaller dump trucks usually have just one rear axle, most heavy-duty trucks have at least two. For even greater capacities, you may want to choose trucks with extra drop axles that you can lower when moving the heaviest loads.
• Tire setup – Some manufacturers are moving from dual tires on each side of the rear axle to "super singles." Super singles help increase fuel economy, but you lose the safety that tandem tires provide in case of a blowout.
• Engine brakes – Jacobs (Jake) brakes and other engine brakes are common on most heavy truck engines. While their use is restricted in many communities, they can really increase brake lifespan if you regularly run long downhill stretches.

Fuel economy
While getting better gas mileage isn't as critical to dump truck drivers as it is to long-haul over-the-road drivers, fuel economy is still an important consideration as you research your truck. After all, any reduction in operating costs goes straight to your bottom line.

The single most important factor to getting the best fuel economy is choosing the right size engine for the work you want to do. If your engine and transmission is underpowered or overpowered, you'll spend more on gas than you should.

Features like aerodynamic styling can also help quite a bit if you're regularly driving at highway speeds – but for dump trucks that stay mostly local, they're not worth the extra expense.