Today's trucks are loaded up with the latest electronics and convenience features. Even an older semi-truck can find itself loaded with a broad range of aftermarket gadgets and other digital goodies—all of which require a reliable source of power. Auxiliary power units, also known as APUs, offer that power without keeping the main truck engine on idle for hours at a time. As you look for the right used semi-truck for your hauling needs, you'll want to learn more about how these accessories can make your new-to-you truck a more pleasant place to live in.

APU Benefits for Your Truck

Fuel savings are a major benefit of using an APU for your semi-truck. According to the U.S. Environmental Protection Agency, the average semi-truck wastes an entire gallon of diesel fuel for each hour it idles. In addition, the excess idling can also release harmful emissions into the atmosphere as well as add wear and tear on the engine itself. APUs use significantly less fuel than the main diesel engine, helping you reduce your semi-truck's overall fuel consumption while lowering fuel costs.

Having your used semi-truck equipped with an APU can also be an effective way of getting around diesel anti-idling ordinances. In areas where idling is prohibited, you can use your APU to supply power for air conditioning, heating, and assorted electronics from laptops to electric cooking stoves. In places where the anti-idling laws also extend to diesel-powered APUs, you can use an all-electric or propane autogas-powered unit instead.

Combustion-Powered Versus All-Electric

There are two types of APUs currently on the market—all-electric APUs that operate on battery power and combustion-powered units powered by diesel, propane, or natural gas. Each type has its own set of advantages and drawbacks to consider.

All-electric APUs run silently and cleanly, resulting in drastically reduced noise and zero emissions. However, an electric APU can only operate for as long as its battery allows it to. All-electric APUs can operate for 8 to 12 hours on a single charge, depending on how much it's being used. These systems usually aren't as effective at keeping the cab cool on hot days as their combustion-engine counterparts.

Diesel, propane-autogas, and natural gas–powered APUs, on the other hand, offer continuous run times as long as they're supplied with fuel. Combustion-engine APUs also offer better cabin cooling and can even supply enough charging power for the truck's batteries. An APU can even be integrated into the semi-truck's engine-cooling circuit, ensuring that the engine can be kept warm during the winter months without the need of a block heater.

Which type of APU you choose depends on your unique wants and needs. For example, if you operate in areas with no-idling ordinances that include all-diesel engines, an all-electric or propane-autogas APU may be your best bet. Otherwise, combustion-engine APUs are a good choice if you want continuous operation without worrying about battery-drainage issues.

Costs and Other Considerations

According to Work Truck Online's Sean Lyden, the average new APU can cost anywhere from $6,000 to $10,000, including the costs of installing the unit in your truck. Many new APUs offer a plethora of different options that can add hundreds or even thousands to the price tag. A used APU may be significantly cheaper to purchase and install, but you'll want plenty of service records to make sure you're not getting a deal that's too good to be true.

Another consideration to keep in mind is where you'll place your new APU. Depending on your truck's chassis configuration, you may end up shifting the fuel tanks or air dryers around in order to make space for your APU.

Talk to a company such as Arrow Truck Sales for more information.