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upgrading your fleet

Upgrade Your Fleet While Saving Money and the Environment

September 26, 2019

Fleet managers are under the immense pressure to keep aging fleets on the road at top performance with as little downtime as possible while: a) spending as little capital as possible, b) reducing operating costs, and c) reducing greenhouse gas emissions to comply with state and federal regulations. Perhaps the easiest way to ensure that a fleet is operating at top performance while saving on fuel costs and keeping emissions compliant is to simply purchase new, fuel-efficient replacement vehicles for the fleet as they age past their useful life. But buying new fleet vehicles is a major cost that most business stakeholders would rather defer as long as possible. This makes extending the useful life of an existing fleet by upgrading with alternative fuel technologies an extremely attractive option for the resourceful fleet manager.

In 2017, the United States Department of Energy’s (USDOE) Office of Energy Efficiency and Renewable Energy published a resource aimed at helping fleet managers to make informed decisions when upgrading fleet vehicles to alternative fuels. This insightful guide provides recommendations on the various alternative fuel types and modifications available. In this blog, we’ll discuss how upgrading an existing fleet through converting, retrofitting, or repowering fleet vehicle motors can help to save money and stay compliant with emissions standards.



Conversion refers to the process of altering a vehicle’s drivetrain to be powered with an alternative fuel or by a power source that is different from its original intended design. This usually refers to modifying a gasoline or diesel engine to run on cleaner and more efficient fuels like propane, compressed natural gas, ethanol, or even hybrid technology. A fleet manager might decide on conversion over purchasing new if the fleet vehicles’ chasses have been modified in some way to accommodate specialized functions for the job at hand (i.e. spray pumps, tanks, toolboxes, lift beds, etc.).

The cost to have these specialized modifications duplicated onto a new vehicle may make it cost-prohibitive to purchase new vehicles. Another reason a fleet manager might choose conversion is the condition of a fleet vehicle’s chassis and interior. If they’re in great shape, but the engine is not performing optimally, conversion may be a more cost-effective solution than purchasing a new vehicle.

Some other considerations for conversion include: What is the environmental impact of conversion versus buying new? Which vendor is best to perform the conversion? Does the conversion kit comply with all local and federal air quality and emissions standards? Are there federal and/or local incentives to convert to alternative fuels? Which alternative fuel conversion suits the fleet driving needs best? These considerations, among others, should weigh heavily when making the decision to convert.



Retrofitting usually refers to adding technologies or hardware to diesel engines that help to reduce greenhouse gas emissions. Retrofitting may also involve adding a parallel fuel system to allow diesel engines to run on other cleaner-burning diesel fuels like ultra-low sulfur diesel, biodiesel, or clean diesel. If a fleet is comprised of older, poor-performing diesel motors, retrofitting may be a great choice for meeting or exceeding EPA standards while upgrading performance over purchasing a new vehicle or motor. Like conversions, there are several federal and state incentives to encourage retrofitting diesel engines for compliance.



Repowering a fleet vehicle usually includes replacing an older engine with a newer more fuel-efficient engine that meets state and federal emissions standards. This can be a complicated solution because older engine compartments may not be properly suited for newer engines that include additional hardware for reducing greenhouse gas emissions. Because of this, repowering can be a more expensive alternative and is usually performed on more heavy-duty fleets versus medium- or light-duty fleets.


The decision whether to buy new or upgrade using one of these three options is an important one with many important considerations. For more in-depth information, please read the full informational guide here.

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