Thomas Built Reports Success With Engine Aftertreatment Adjustment
Some school districts are seeing significant drops in DPF-related maintenance issues after using the "Stay Warm" feature for Cummins diesel engines.

Some school districts are seeing significant decreases in DPF-related maintenance issues after using DPF temperature stabilization in their buses with Cummins diesel engines.

Some school districts are seeing significant decreases in DPF-related maintenance issues after using DPF temperature stabilization in their buses with Cummins diesel engines.
HIGH POINT, N.C. — Some school transportation providers are seeing success using a feature designed to optimize performance in Cummins diesel engines.
Last year, Thomas Built Buses announced that it had begun offering the new feature, known as diesel particulate filter (DPF) temperature stabilization or “Stay Warm.” The new feature is designed to optimize the regenerative parameters of diesel engines, increasing active regeneration and decreasing aftertreatment DPF maintenance issues. Over the past year, Thomas Built dealers have been implementing the Stay Warm feature in diesel school buses across North America.
While some school districts are seeing up to a 75% decrease in aftertreatment-related issues, other school districts now have zero DPF-related maintenance issues, according to Thomas Built Buses.
“We have had phenomenal results with the new Stay Warm feature,” said David Walton, vehicle services coordinator for Prince William County Public Schools in Manassas, Virginia. “We now only have one-off regeneration issues, a dramatic reduction from where we used to be. The minimal issues we have now are not even in the same ballpark as what we’ve experienced in the past.”
In partnership with Cummins, the Stay Warm feature is standard and factory-installed on all Cummins engines with a standard exhaust configuration starting April 11, 2017. Thomas Built dealers can also have the engines programmed with the Stay Warm feature for customers with buses with older Cummins engines (model year 2010 or later).
Patty Waites, the assistant director of transportation for Hamilton Southeastern School District in Fishers, Indiana, was one of the first customers to receive the Stay Warm update.
“A representative of Cummins came by and changed the parameters of all of our buses," Waites said. "Since the parameter change, we have had zero DPF issues. We just love it.”
Some Thomas Built customers are also training drivers on more fuel-efficient driving techniques to further increase the efficiency of their diesel engines.
“Changing the parameters has definitely helped us a lot. We went from six to seven regens a day in the shop to a total of four a week,” said Charlie Turvin, fleet trainer for Loudoun County (Va.) Public Schools. “But changing parameters is not the only change we made in our shop. We also taught our drivers how to reduce idle time, how to handle a regen, and the proper gear to drive in.”
“We are thrilled that fleets are seeing significant improvement in their engine and DPF performance due to the Stay Warm feature,” said Caley Edgerly, president and CEO of Thomas Built Buses. “Diesel is one of the cleanest fuels available today and with this feature, fleets can now experience reduced engine maintenance and costs, as well as fleet downtime.”
More Maintenance

BendPak Launches Ranger DST30PX Wheel Balancer
BendPak's new wheel balancer handles tires up to 43 inches in diameter, with a reinforced design, precise weight placement, and faster service cycles.
Read More →
Tips for Ensuring School Bus Garages Are Safe and Warm Year-Round
Cold maintenance bays and rising heating costs? Learn how school bus garages can improve comfort with targeted heating, better airflow, and winter preparation.
Read More →
ASE Highlights School Bus Technician Certification Requirements
ASE is encouraging school bus maintenance professionals to maintain their certifications, highlighting seven specialized tests and five-year renewal requirements.
Read More →
International Adds E-Commerce Capabilities to Fleetrite.com
IC Bus customers can now browse, buy, and track shipments for more than 400,000 aftermarket parts online.
Read More →
The Most Expensive Thing You Do Before Selling a School Bus: Wait
When should you sell an aging school bus? Learn how maintenance, mileage, corrosion, specifications, and timing can affect resale value long before the auction.
Read More →
The Evolution of DEF Header Technology: What School Bus Operations Should Know at Replacement Time
See what school bus fleets should consider when replacing DEF headers to improve reliability, reduce repeat repairs, and control maintenance costs.
Read More →
The Essential Guide to School Bus Maintenance and Student Safety
Your district's buses carry students to school every day. This guide shows how predictive maintenance powered by fleet data helps keep buses reliable, drivers accountable and students safer from the first bell to the last stop.
Read More →
Kerry Brothers Grows Michigan School Bus Repair Network
The acquisition of Downriver Truck and Bus expands Kerry Brothers’ school bus maintenance footprint across southeast Michigan, adding repair capacity, diagnostic resources, and state inspection support.
Read More →
Noregon Introduces CAN Bus Diagnostic Tool, Expands JPRO Features
CAN Mentor and the latest JPRO update aim to simplify vehicle network diagnostics and improve repair efficiency for technicians of all experience levels.
Read More →Cummins on Smarter, Simpler Engine Innovation
Cummins discusses its first-ever gasoline engine for school buses, EPA 2027, and why bus fleets still want durable, simpler internal combustion options.
Read More →
