The first step in vehicle acquisition isn’t necessarily evaluating what it needs to do. Ask yourself if you really need that truck. In addition to upfront costs, eliminating unnecessary units could reduce routine maintenance and licensing costs and labor requirements.
Just because a truck is in the fleet doesn’t mean that it must be replaced with the same model. It may have been bought to meet a requirement that no longer exists. Multiple trucks may be performing the same basic task.
“Rightsizing” should be a part of every replacement cycle’s evaluation process. Do you have a specialty unit that’s only used occasionally? If so, maybe the work can be subbed out to a rented unit.
Rethinking engine options
Fuel efficiency largely depends on how a vehicle was initially designed. Start a new vehicle search by selecting a truck that’s close in size and type to the desired result. It’s usually cheaper to pay for the proper base than continually adding components to an insufficient vehicle.
Also, just because you’ve always used a gas engine or a diesel engine doesn’t necessarily mean it’s the correct choice going forward. This is especially true for trucks in the Class 3-5 range, where gasoline engines have improved and diesel engines have become more expensive as a result of post-2010 emissions requirements. Once engine type is determined, you can take the time to optimize the total powertrain (engine, transmission, axle gearing) to perform at maximum fuel efficiency.
Adding components may increase productivity, but there are tradeoffs. Along with upfront cost, add-ons may increase overall weight, leading to less payload and higher maintenance costs. The extra weight and increased engine idle time could also hurt fuel economy.
In many cases, selections will be guided by the drive and duty cycles. For example, aerodynamic add-ons are highly beneficial when you have a drive cycle that includes extended driving at highway speeds and a duty cycle that includes frequent implementation of that drive cycle.
Before adding components, calculate their long-term benefits using a net present value (NPV) lifecycle cost analysis. An NPV analysis can be used to evaluate both upgraded truck chassis components and productivity add-ons.
Other fuel consumption factors are:
- Low rolling resistance tires
- High-efficiency transmissions
- Synthetic lubricants, especially in gear boxes
- Low-drag brake systems
- High-efficiency accessories such as air conditioning units, air compressors, and alternators.
Know your options. The more you know the chassis OEMs offer, the easier it is to specify an optimum truck.
If a truck isn’t properly designed for the intended application, maintenance costs will increase. But avoiding overload can be tricky. Go beyond traditional GVWR, GAWR, and GCWR measurements and look at how specific applications impact individual chassis components. Identify common high-maintenance components related to the truck’s drive and duty cycles.
- A transmission that’s loaded at or close to maximum horsepower input rating will probably run hot, which may mean a higher failure rate. Consider upgrading the transmission or adding auxiliary cooling units.
- A low-output air brake compressor used in an inner city/urban application may have an excessively high run-time profile, which, in turn, can reduce the unit’s useful life. If an analysis of your fleet’s maintenance issues shows a high failure rate in such an application, consider a larger compressor to shorten recharge cycles.
- Trucks with high static loadconditions, typical of utility trucks equipped with heavy mounted equipment, exhibit frequent spring failures simply because the springs are never allowed to relax. If some of your applications fall into this category, look into using spring packs rated at least one step higher than the associated axle and tire ratings.
Look at your fleet’s maintenance history and identify high-failure components and systems. They will likely be associated with overloading, whether in terms of actual load imposed by the truck’s application or from an excessively high utilization rate. Use the replacement cycle to correct these issues.
Robert Johnson is director of fleet relations for the National Truck Equipment Association. Visit www.ntea.com.