Rightsizing Your Vehicle Fleet to Conserve Fuel

Photo of a vehicle fleet

Fleet rightsizing is a management practice that can help vehicle fleet managers build and maintain sustainable, fuel-efficient fleets. Fleet inventories often grow over time to include vehicles that are highly specialized, rarely used, or unsuitable for current applications. By optimizing fleet size and composition, managers can minimize vehicle use, conserve fuel, reduce emissions, and save money on fuel and maintenance.

Evaluate Vehicle Needs and Use

Fleet managers should understand their drivers' daily vehicle use and needs. Most fleet managers already have a handle on vehicle quantities, types, average mileage, payloads, and fuel economy. Fleet rightsizing combines this information with a critical look at fleet operations to identify opportunities for reducing fuel use. When rightsizing, fleet managers should evaluate how important each vehicle is to the fleet’s performance by asking themselves:

  1. What is the optimal number of vehicles required to properly support the fleet’s needs?

  2. What tasks are accomplished by each vehicle? Or, what is the drive cycle?

  3. What is the daily, weekly, or monthly mileage of each vehicle? Or, what is the duty cycle?

  4. Are fleet vehicles the optimal vehicle type, class, and size for the job?

  5. Are there any vehicles that are no longer cost effective to operate or no longer fulfilling their purpose?

  6. Are there any vehicles that are no longer being used or have a lot of downtime?

  7. Can any vehicles be replaced by lighter, more fuel-efficient vehicles?

  8. Are there any alternatives to owning or leasing a vehicle, such as shuttle bus services, motor pool vehicles, sharing vehicles with other offices/agencies, public transportation, or short term rentals when needed?

Case Study

The City of Detroit generated $1 million in revenue working with the Clean Energy Coalition to rightsize the city's fleet by selling surplus vehicles and equipment.

Fleet managers should consider soliciting input from drivers when conducting a rightsizing review, as they can be very knowledgeable about how vehicles are being used to support operations. Gathering this input also gives drivers a stake in the development of rightsizing recommendations. Fleet managers can solicit input through driver surveys or face-to-face meetings to establish consensus.

A fleet rightsizing strategy should evaluate the business case of each vehicle to determine whether reassigning, replacing, or eliminating the vehicle would reduce fuel and maintenance costs without compromising fleet activities. Fleet managers often need to define evaluation criteria and rank vehicles to complete this analysis. A fleet dominated by sport utility vehicles, for example, may find that mid-size sedans can suffice with a significant reduction in fuel costs.

Fleet managers may develop their own analysis or use existing evaluation tools. The Vehicle Allocation Methodology developed by the U.S. General Services Administration is an evaluation framework that federal agency fleets use to ensure fleets are cost-effective and contain the appropriate number and type of vehicles. Learn more about this methodology in the Comprehensive Federal Fleet Management Handbook.

Make Smart Vehicle Purchases

State and Local Laws

Maine has a law requiring fleets to purchase fuel-efficient vehicles to help the state fleet conserve fuel, save money, and reduce emissions.

Fort Lauderdale, Florida, also developed fleet rightsizing and idle reduction policies to ensure that their fleet uses the most fuel-efficient vehicles while still meeting their fleet needs.

Fleet managers may decide to replace older vehicles with more fuel-efficient or alternative fuel vehicles. These purchasing strategies may help fleet managers make decisions that meet operational needs and conserve fuel:

  • Transition to Smaller, More Efficient Engines: Using smaller engines can help fleets meet operational needs without downgrading vehicle class. Some fleets choose to switch from 6-cylinder to 4-cylinder engines to help reduce fuel use and emissions. In many cases, the new, smaller engine can have nearly the same horsepower as the older, larger engine.

  • Choose Lighter Vehicles: When purchasing new vehicles, look for opportunities to reduce vehicle weight. Lightweight materials, such as aluminum frames, and smaller components can reduce a vehicle’s fuel consumption. For example, a 10% reduction in vehicle weight can improve fuel economy by 6%–8%. Also, try to avoid unnecessarily large body configurations and heavy accessories.

  • Use Alternative Fuels and Vehicles: Alternative fuel and fuel-efficient advanced vehicles can reduce a fleet's fuel use, making them economical options for many fleets. Cost savings from vehicle maintenance, operation, and fuel use often offset higher purchase prices.

Fleet managers can blend the strategies that will provide them the greatest benefit.

Find light-duty vehicle fuel economy information in the most recent Fuel Economy Guide.