Vehicle Parts and Equipment to Conserve Fuel
There is plenty of wasted energy in the traditional combustion engine, especially in modern day vehicles. Most of the energy is lost to engine and driveline inefficiencies like exhaust heat, or used to power accessories like climate control such as air conditioning. Vehicle fleet managers and drivers can conserve fuel and maximize their operational efficiency by driving efficiently and outfitting their vehicles with commercially available equipment designed to save fuel. Implementing fuel-efficient strategies, systems, and programs for some or all vehicles can help fleets monitor and manage their vehicles and vehicle-related costs better. These strategies are cost-efficient and do not require extended vehicle downtime.
Low Rolling Resistance Tires
Rolling resistance is the energy lost from drag and friction of a tire rolling over a surface. This phenomenon is complex, and nearly all operating conditions affect how much energy is lost. With the exception of all-electric vehicles, passenger vehicles use about 4%–11% of their fuel just to overcome tire rolling resistance. For heavy trucks, this consumption can be higher, around 15%–30%. A 5% reduction in rolling resistance would improve fuel economy approximately 1.5% for light- and heavy-duty vehicles. Installing low rolling resistance tires can help reduce fuel costs. The U.S. Environmental Protection Agency's (EPA) SmartWay program provides lists of verified low rolling resistance tires and tire technologies.
In Class 8, replacing traditional dual tires with one wide-base (also called super-single or single-wide) tire can save fuel by reducing vehicle weight and rolling resistance, which means the engine doesn't need to work as hard. A wide-base tire is not quite as wide as the sum of the two tires, so there is a slight aerodynamic benefit as well, further improving vehicle efficiency. Using wide-base tires can improve fuel efficiency by approximately 5%.
Aerodynamic Equipment and Vehicle Design
By reducing the drag, or resistance, imposed on a vehicle traveling at high speeds, aerodynamic equipment eases the load on the engine and improves the fuel economy of a vehicle. Airfoils, trailer gap reducers, side skirts, and tails are examples of aerodynamic equipment that fleets can install on trucks to reduce driveline losses. Airfoils direct air over the cab, trailer gap reducers lessen air turbulence by minimizing the space between the cab and the trailer, side skirts limit the air that circulates under the trailer, and tails reduce the turbulent airstreams dragging behind the trailer. EPA's SmartWay program provides lists of verified aerodynamic devices.
Many light-duty and heavy-duty vehicles (HDV) that manufacturers are developing have streamlined vehicle designs that reduce drag. More information on aerodynamic tractor and trailer equipment for HDVs can be found in the North American Council for Freight Efficiency's Confidence Reports.
Idle Reduction Equipment
Idle reduction technologies reduce the amount of time an engine idles unnecessarily. Auxiliary power units (APUs), bunk heaters, batteries, and other idle reduction equipment can help reduce idling and save fuel. EPA's SmartWay program provides lists of verified idling reduction technologies for trucks and school buses. A number of tools developed by Argonne National Laboratory, such as the Idle Reduction Savings Calculator, help fleet managers and drivers calculate the time they idle, allowing them to identify the most cost-effective ways to improve their idling profile and identify potential savings.
Long-haul fleets can take advantage of electrified parking spaces, also known as truck stop electrification, which provide power to necessary systems such as heating, air conditioning, or appliances without idling the engine. Fleets can also install equipment on vehicles to improve their efficiency and conserve fuel (see example case studies for fleets in Portland, Oregon, and St. Louis, Missouri). Many of these investments have short payback periods.
Fuel-Tracking Devices and Telematics Systems
Data collection devices installed in vehicles can track fuel economy, maintenance schedules, and fleet performance to help fleets monitor fuel consumption, improve fuel economy, and increase asset utilization. For example, the Public Service Company of New Mexico’s fleet installed a telematics system to monitor fleet performance, track driver behavior, and inform driver training. With these devices, the fleet improved their average fuel economy by 15%.
Electronic logging devices automatically record hours-of-service and driving time data and are required on certain commercial buses and trucks. Through the use of Global Positioning Systems (GPS) and communication technologies, telematics provide fleet managers with data about vehicle location, vehicle use and miles driven, idle time, fuel economy, driver behavior, and engine maintenance requirements. Many of these telematics systems are paired with powerful software packages or driver training programs to help track vehicle activity and manage fuel consumption. Some devices give drivers real-time fuel economy feedback, which has proven effective in reducing fuel use. Other devices can also help fleets identify which vehicles to evaluate for potential replacement.
To determine what telematics systems data to focus on, a fleet should identify its top priorities, such as idle reduction or efficient routing. The fleet can then work with a telematics provider to determine key performance indicators and extract the most important data. This planning will help the fleet use the data to deliver efficiency improvements. Learn how Pepsi used dynamic route optimization software to create more efficient routes and save fuel. In a telematics deployment study with the Marine Corps fleet, researchers at the National Renewable Energy Laboratory calculated the total savings from telematics for various light-duty vehicles and shuttle buses. When used in the Marine Corps fleet, telematics had the potential to help fleet managers save more than $2,000 per vehicle each year.
Speed Control Modules
Fleet managers can install electronic speed control modules to prevent vehicles from traveling faster than a specific speed, which can conserve fuel and promote safer driving practices. For example, Braun's Express, a trucking fleet in Massachusetts, installed electronic control module systems in each of its short-haul and long-haul freight trucks to control fuel consumption and limit speed. By reducing the maximum speed of its vehicles from 70 to 65 miles per hour, Braun’s increased overall fuel economy by an estimated 0.5 miles per gallon for each vehicle.