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
and equipment 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, operations managers and maintenance technicians have been forced to make a trade-off.
The DPFs downside
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. Each regen requires
incremental fuel use, decreasing fuel economy and often forcing
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.
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 contribute heavily to ash buildup in the DPF. Despite regen cycles, this means eventual DPF clogging, resulting in increased service intervals, unnecessary downtime or costly replacement.
The cost of Tier 4 Final
Tier 4 Final engines are here for heavy-duty off-
highway vehicles—and have been for a while now.
Many fleets are already operating with 25% Tier 4
Final equipment. And that number is only going to
grow. But there has been a resistance to embracing
this technology due to associated costs. Learn more
about how ash clogging in the DPF could be costing
The DPF impact on
Take a deeper dive on how fuel efficiency is
negatively impacted by oil contaminant clogging
Cleaning the DPF
See how the DPF is measured for resistance and
then cleared with high air pressure in a
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.
Maintenance issues and
Understand the causes related to ash clogging in
your DPFs and why you may be servicing them
more than OEM guidelines suggest.
Clogged DPFs and the “Fuel
Is your engine burning fuel at a faster rate? It
may be because ash is clogging your DPF,
causing backpressure and forced regenerations.
Modal Component - Modals Configured