Webasto Releases DPF Test Results
An Independent Emissions Testing Lab recently tested the effects of a Webasto coolant heater on the emissions performance of a diesel engine.
An Independent Emissions Testing Lab recently tested the effects of a Webasto coolant heater on the emissions performance of a diesel engine. To simulate different temperature conditions during the seasonal changes and the effect caused by the Webasto heater, boundary conditions to the test engine were set at 40 degrees Fahrenheit and 75 degrees Fahrenheit during separate test runs.
Emissions testing using an AC transient engine dynamometer, was performed to determine the effect of engine start-up temperature on PM, HC and CO emissions on a 2005 DT466 engine using an FTP Transient cycle with a Webasto Thermo Top C 5 Kw coolant heater (Part Number 923369). Emissions data shows that the start-up temperature has a significant effect on the engine emissions and overall performance of DPFs.
Results Summary:
Engine start-up temperature has a significant impact on the emissions levels emitted by the engine.*
PM emissions were reduced by 66 percent by pre-heating the engine during the cold weather conditions. Pre-heating also provided a 27 percent reduction in PM emissions during normal ambient conditions. This will help in longevity of the DPF life and can avoid more frequent regenerations and cleaning intervals.*
NOx emissions were reduced by around 40 percent by pre-heating the engine to 155 degrees Fahrenheit.*
The test results shows a 29 percent reduction in CO during winter conditions, and a 62 percent reduction during normal ambient conditions.*
Pre-heating the engine does not have a significant effect on the Hydrocarbon emissions.*
*Source: ESW America Inc. Results will vary based on engine size, duty cycle and overall maintenance. FTP Cycles ran did not follow all the CFR testing requirements as test cell conditions were controlled to represent cold conditions.
Webasto officials willingly share the results and state “The independent testing results show that pre-heating engines improves DPF performance and longevity along with extending the duration between cleaning cycles on engines that do not run a heavy duty cycle. Even engines in warm climates of 70 – 80 degrees Fahrenheit (for example) are not completely warm until they reach 130 degrees Fahrenheit and higher for optimal performance. Webasto coolant heaters provide optimal temperature at start-up.”
RELATED CONTENT:
More Maintenance

Coltrain Onsite Fleet Care Launches SHIELD, a Purpose-Built Field Service Application
As Coltrain Onsite marks its first year of operations, having grown to more than 100 team members across 14 states, the company is launching SHIELD, its proprietary field service application designed to set a new standard for quality in mobile fleet maintenance.
Read More →
Preparing Your Fleet for Extreme Heat
Hot weather puts extra stress on commercial vehicles. In this video, Mike Hagaman of Cox Fleet shares simple maintenance steps that can help fleets avoid costly downtime.
Read More →
Fleetio Launches PartsTech Integration, Potentially Helping Fleets Save up to 15 Minutes on Each Purchase Order
Fleetio’s integration with PartsTech brings parts sourcing and ordering into a single connected Fleetio workflow, reducing administrative work and potentially saving users up to 15 minutes per purchase order.
Read More →
6 Main Causes of Hot-Weather Fleet Downtime
Summer heat can lead to costly fleet downtime. In this video, Mike Hagaman of Cox Fleet explains the six key systems fleets should inspect and maintain to help prevent roadside breakdowns.
Read More →
ASE Connects’ Back-to-School Giveaway: Schools Can Win Tools and Prizes from Snap-on
As part of a back-to-school giveaway, ASE Connects and Snap-on will provide four schools with prizes, including three $250 Snap-on gift cards and a grand prize of a Snap-on cart and tool set valued at over $11,000.
Read More →
BendPak Opens Donald R. Henthorn Industrial Complex in Alabama
BendPak has completed Phase 1 of construction of the Donald R. Henthorn Industrial Complex, which includes a new logistics and distribution center. The complex is situated on 33 acres near BendPak’s existing East Coast campus in Mobile County, Alabama.
Read More →
As Maintenance Costs Rise, Some Work Trucks and Vans Cost Thousands Less to Maintain
Maintenance costs are still climbing, but some 2026 pickups and cargo vans could save fleets thousands per vehicle. The real surprise is not just how much they cost to maintain, but how often they need to leave the road.
Read More →
Kerry Brothers Truck Repair Expands Rapidly Across Southeast Michigan with 3 Acquisitions and New Wixom Facility
Acquisitions of Kustom Truck & Trailer, Vehicle Clinic and Downriver Truck and Bus, along with a new 20,000-square-foot Wixom facility, extend Kerry Brothers’ footprint east, south, west and north across the greater Detroit region.
Read More →
Kooner Fleet Management Solutions Named Fleetio Premier Partner
Fleetio has named Kooner Fleet Management Solutions as a Premier Partner within Fleetio’s Maintenance Shop Network. As a Fleetio Premier Partner, Kooner's designation reflects its commitment to delivering reliable maintenance services and supporting fleets through high-quality service.
Read More →
Proven Ways to Reduce Work Truck Downtime
The age-old problem of downtime will always be a reality, but with new strategies at hand, fleets have more ways to keep trucks on the road longer.
Read More →
