How emissions control is challenging efficiency

Over the past few decades, the Environmental Protection Agency (EPA) has implemented emissions regulations for heavy-duty diesel engines—for both on and off highway. While these standards are positive and have lowered emissions, the engine aftertreatment systems (EATS) now mandatory in all new vehicles bring their own set of unique challenges when it comes to overall efficiency and total cost of ownership.


The diesel oxidation catalyst (DOC) converts CO into CO2, oxidizing unburnt hydrocarbon emissions to increase the temperature of the exhaust, which aids the DPF function.

The diesel particulate filter (DPF) collects up to 98% of particulate matter emissions in the form of ash & soot. Ash is incombustible material derived from metallic lubricant additives.

In the selective catalytic reduction (SCR) unit, diesel exhaust fluid (DEF), in conjunction with the catalyst, converts NOx into N2 & H2O.

The EATS trade-off

The latest category of heavy-duty engine oils were specifically designed to protect this latest generation of engines, but oil technology has not advanced far enough when it comes to optimizing and protecting the aftertreatment system, especially with regards to the diesel particulate filter (DPF). Consequently, fleet owners and operations managers have been forced to make a trade-off—one that requires more fuel.

How DPFs increase fuel consumption
What's actually happening?

DPFs play a crucial role in cleaning diesel exhaust before it hits the tailpipe, reducing emissions of particulate matter (PM). As fuel burns, the DPF collects and stores up to 98% of incombustible particles in the form of ash and soot.

DPF regeneration cycles

Once enough soot and ash accumulate, the engine initiates a process where extremely high temperatures burn off the collected particles to regenerate the DPF. Regen cycles can be passive or active and both require additional fuel to run, decreasing fuel economy.

Ash clogging in the DPF

Soot burns off through regeneration, but ash remains in the DPF. Engine lubricants contain metallic additives, such as anti-wear and detergents, which clog the DPF and create backpressure. On top of regeneration cycles, this backpressure puts additional strain on the engine, causing a significant increase in fuel consumption.


Fueling fleets

Whether you operate a large fleet, a small fleet or something in between, effectively managing fuel costs is crucial to your business’s profitability. DPF clogging due to ash buildup causes more frequent regenerations and backpressure, which increases fuel consumption. And those numbers can add up quickly across your fleet.

See the business impact
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    The DPF impact on
    fuel economy

    Take a deeper dive on how fuel efficiency is negatively impacted by oil contaminant clogging in DPFs.

    Get the report
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    Cleaning the DPF

    See how the DPF is measured for resistance and then cleared with high air pressure in a pneumatic cleaner.

    Watch the video
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    Inspecting the DPF

    See how the honeycomb filter collects and stores ash and soot to prevent harmful emissions.

    Watch the video
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    Cleaner air and lower-ash

    See how landmark legislation on air quality has had a far-reaching impact on diesel engine design, producing a need for lower-ash oils.

    Read the blog
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    Maintenance issues and
    aftertreatment systems

    Understand the causes related to ash clogging in your DPFs and why you may be servicing them more than OEM guidelines suggest.

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    Clogged DPFs and the “Fuel Penalty”

    Is your engine burning fuel at a faster rate? It may be because ash is clogging your DPF, causing backpressure and forced regenerations.

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Welcome to the Emissions Control Center

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