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Webasto: Test results show benefits of pre-heated engines

An independent emissions testing lab recently tested the effects of a Webasto coolant heater on the emissions performance of a diesel engine. Emissions data show that the start-up temperature has a significant effect on the engine emissions and overall performance of diesel particulate filters.

November 19, 2013
2 min to read


FENTON, Mich. — 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.

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Emissions testing using an AC transient engine dynamometer was performed to determine the effect of engine start-up temperature on particulate matter (PM), hydrocarbon (HC) and carbon monoxide (CO) emissions on a 2005 DT466 engine using an FTP transient cycle with a Webasto Thermo Top C 5-kW coolant heater. Emissions data show that the start-up temperature has a significant effect on the engine emissions and overall performance of diesel particulate filters (DPFs).

Webasto released the following results summary from the test:

• Engine start-up temperature has a significant impact on the emissions levels emitted by the engine.

• PM emissions were reduced by 66% by pre-heating the engine during the cold weather conditions. Pre-heating also provided a 27% reduction in PM emissions during normal ambient conditions. Officials said that 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% by pre-heating the engine to 155 degrees Fahrenheit.

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• The test results show a 29% reduction in CO during winter conditions and a 62% reduction during normal ambient conditions.

• Pre-heating the engine does not have a significant effect on the HC emissions.

The source of these findings is ESW America Inc. Officials noted that results will vary based on engine size, duty cycle and overall maintenance.

“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,” Webasto officials said in a statement. “Even engines in warm climates of 70 to 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.”

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