Emissions

Exhaust Gas Recirculation (EGR)

Exhaust Gas Recirculation (EGR) is an emission control strategy that offers significant reduction in NOX emissions from internal combustion engines. EGR was applied in light-duty gasoline and diesel-fueled vehicles in the mid-1970s and has transferred over to heavy-duty diesel engines from the early 2000s.

As of the 2008 model year, Yanmar has implemented EGR technology as part of its strategy for engines above 56 kW (75 hp) to meet the Tier 3 and Stage IIIA emissions regulations.

EGR is a method by which a portion of the engine’s exhaust gas is reintroduced to the combustion chamber through the intake system. The primary of effect of EGR, reduction of NOX, is created by reduction in combustion temperatures. Reduction of NOX does come with an increase to other exhaust constituents: PM, HC and CO emissions. However, Yanmar has taken the effort to implement additional engine modifications: electronically-controlled fuel injection, combustion and fuel injection optimization. Yanmar’s efforts also minimize the impact EGR would normally have on fuel economy and power density in order to provide you the same platform for all applications and ensuring compliance to the most stringent emissions regulations in effect.

The figure above is a representative schematic of a standard EGR System. Some engines employ the engine’s coolant to reduce the exhaust gas temperature prior to reintroduction to the combustion system further reducing NOX emissions.

Emissions Regulations

The EPA and EU are at the forefront for establishing the most stringent standards in effect today. Exhaust performance and testing requirements put the responsibility on the manufacturer to design and establish the most advanced engine control technology available. Implementation of the emissions regulations are in tiers with exhaust requirements becoming more stringent at each step.

Tier 1/Stage I and Tier 2/Stage II
Required manufacturers to optimize fuel injection and combustion performance; internal engine modifications.

Tier 3/Stage IIIA
Required an approximate 60 percent reduction in particulate matter (PM) and a 50 percent reduction in oxides of nitrogen (NOX) from first standards established in 1996.

Tier 4/Stage V
Requires manufacturers to further reduce both PM and NOX emissions by approximately 90 percent; nonroad engines will be at near-zero levels.

Certificates

To help identify the appropriate certificate of conformity, you will need to:

1. Locate the emissions control information label on the engine (valve cover).

   

2. Note your engine’s information.
   • Model Year
   • Engine Family
   • Engine Model
3. For CARB Executive Orders:
   • Go to website http://www.arb.ca.gov/msprog/offroad/cert/cert.php
   • Select Equipment Category: Offroad Compression-Ignition Engines (Diesel)
   • Select Model Year: example “2008”
   • Select: “Regular”
   • Click Browse
   • Select Manufacturer. Scroll to bottom of list and select all of the “Yanmar” company names.
   • Click Submit
     Example: Look for Engine Family 8YDXL3.32C4T and select Executive Order U-R-028-0403
     Make sure to locate the engine model number on the executive order.

   For EPA Engine Certification Data:

   • Go to https://www.epa.gov/compliance-and-fuel-economy-data/annual-certification-data-vehicles-engines-and-equipment
   • Download the Excel file corresponding to the requested engine type (nonroad compression ignition, marine compression ignition, etc.)
   • Search for “Certificate #” by filtering “Yanmar” and “Engine Family”.