The emission control equipment is also placing more demands on the modern diesel engine.
Fuel Sulfur Reductions from 5000 ppm to 500 ppm
Engine Hardware Modifications such as the addition of Exhaust Gas Recirculation (
EGR)
These methods alone are no longer enough to reach the new Emission levels.
Heavy duty on road diesel exhaust first began to be regulated in 1988. Since then, five exhaust emissions “tightenings” have occurred with the sixth occurring in 2007. The latest emission regulation will have reduced emissions by 90% compared to the 2002 level.
The above chart shows on-highway requirements. Emissions requirements for off-highway equipment will also become more severe. Off-highway standards are scheduled to start in 2011 and become similar to on-highway requirements by 2014.
Since 1994, particulate matter standards have been constant and only Nox has been consistently reduced. Now, 2007 not only continues to reduce Nox but also particulates are considerably reduced. In 2010, Nox will be reduced once again.
Meeting 2007 Emissions Requires More Changes
- Exhaust Gas Recirculation (EGR) increases from 15% to 30%
- Diesel fuel sulfur reduction from 500 ppm to 15 ppm
- Diesel Particulate Filters (DPF’s)
- Selective Catalyst Reduction (SCR)
- Closed Crankcase Ventilation (CCV) is required.
Cummins, DDC, Mack and Volvo use Cooled EGR to meet the new NOx (nitrogen oxides) requirements.
Caterpillar is the only exception, and uses Advanced Combustion Emission Reduction Technology (ACERT) combined with remote EGR.
Lowering NOx and EGR cause “Wear Challenges”
While cooling exhaust gas lowers the flame temperature which reduces NOx, it also increases the Acid in the cylinder.
Cooling exhaust from 1200 F to 300 F using the coolant increases the heat to the coolant by 25-30% and raises top-tank coolant and oil temperatures.
The October '06 API CJ-4 Specification is by far the most comprehensive and expensive HDD category in history! Combining API CJ-4 (diesel engines) with API SM (gasoline engines) is very expensive … costing upwards of $1M. However, this specification is necessary to ensure compatibility with exhaust treatment devices introduced in the 2007 model year. It will also increase engine protection and durability.
While it was designed for 2007 vehicles, it is backwards compatible. Without advancements in engine oil technology, engine builders would not have been able to meet the emissions requirements without major reductions in engine life, and or service intervals.
What are the implications of the OEM emissions strategies?
Well, Doubling EGR rates from 15% to 30% will increase soot and acids. Closed Crankcase Ventilation will increase the overall stress on the lubricant. This all means that {quotes}engine oils will be subject to more severe environments than ever before{/quotes}
oil drain intervals will decrease for new ‘07 hardware (all other factors constant).
So what is the diesel engine oil solution for 2007?
AMSOIL Synthetic 5W-40 Premium
API CJ-4 Diesel Oil (DEO)
Broad viscosity range replaces competitive 5W-40, 10W-40 and 15W-40 viscosities
Excellent hot and cold temperature performance
Backward compatible with older engines
Maximum TBN of 8 due to Sulfated Ash limitations
Extended drain intervals when monitored by oil analysis in new and old engines.
