Town of Cary
Home MenuIdle Reduction Technology & Sustainability in the Cary Fire Fleet
Reducing Emissions on the Front Lines
What Is Idle Reduction Technology (IRT)?
IRT powers down a truck’s diesel engine when it’s not actively in use (like during EMS calls), while maintaining power to lights, HVAC, and radios using a dedicated lithium-ion battery system.
Why Idle Reduction Matters
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Reduced fuel and diesel exhaust fluid (DEF) costs
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Lower engine maintenance needs and longer service intervals
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Quieter operation improves operator health and safety
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Decreased emissions and environmental impact
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Reduced operational costs for each apparatus
Cary’s fire apparatus fleet is essential to public safety—and also a major consumer of diesel fuel. While fully electric vehicles are on the horizon, IRT allows us to take immediate action by significantly cutting emissions and fuel waste in our existing and incoming diesel-powered fleet.
In Action: From Retrofit to Frontline
Cary operates 23 heavy-duty fire trucks, with most running 15 years as a frontline vehicle and five years as reserve. These trucks spend a significant portion of that time idling—on average, a cumulative total averaging over 12,000 hours per year.
To reduce environmental impact and operating costs, Cary began adding IRT to its fleet in 2022, starting with nine existing units being retrofitted. All new units are fully equipped with IRT from the manufacturer. Each IRT unit saves an estimated 8.23 metric tons of emissions annually—roughly equivalent to taking two passenger vehicles off the road.
A Steppingstone to Electric – Where IRT Fits in the Big Picture
As part of a phased approach to fleet modernization, Cary sees IRT as a crucial step between diesel and electric fire apparatus. In 2021, Cary submitted interest in Pierce Manufacturing’s pilot program for electric vehicles—and in Spring 2025, received and operationalized the Pierce Volterra pumper, the first electric fire truck on the East Coast.
Smart Investment, Sustainable Future
The retrofit cost for IRT is approximately $36,000 per unit, with a projected return on investment within four to eight years. As diesel and maintenance costs rise, these savings are expected to grow.
From Retrofit to Resilient
With IRT now standard in new orders and retrofitted in select vehicles, Cary is on track to fully transition to IRT-equipped apparatus by FY40—without compromising emergency readiness or service delivery.