Emissions Evolution For Doosan Equipment

Doosan® machines have been changing to meet emission standards for several years. Many Doosan equipment models will go through as many as five different tiers of standards: Tiers 1-3, Interim Tier 4 (iT4) and Tier 4 (T4).
You don’t have to retrofit your machines to the current emission standards. Federal regulations require that manufacturers build machines compliant with the emission standards in effect at the time of manufacture.
Standards for diesel exhaust emissions become more stringent from tier to tier. Each tier addresses numerous types of pollutants. However, Particulate Matter (PM) and Nitrogen Oxides (NOx) receive the most attention.
  • Nitrogen Oxides (NOx) contributes to ground level ozone, commonly known as smog.
  • Particulate Matter (PM) consists of soot or unused fuel found in exhaust. This type of pollution gives dirty engine exhaust its black color.


Chart 1 explains how harmful emissions such as NOx and PM are reduced through each emission tier.

Chart 1

All Tiers - Doosan Equipment
Engine Horsepower19961997199819992000200120022003200420052006200720082009201020112012201320142015
50-75Tier 1Tier 2Interim Tier 4Tier 4
75-100Tier 1Tier 2Tier 3Interim Tier 4Tier 4
100-175Tier 1Tier 2Tier 3Interim Tier 4Tier 4
175-300Tier 1Tier 2Tier 3Interim Tier 4Tier 4
300-600Tier 1Tier 2Tier 3Interim Tier 4Tier 4

Tier 1 for Doosan Equipment
The first set of EPA emission standards for new non-road diesel engines is referred to as Tier 1 (date range shown in chart 1). The main goal of this emission tier was to reduce Nitrogen Oxides (NOx) emissions from these engines by roughly 30%.

Tier 2 for Doosan Equipment
The second set of EPA emission standards for new non-road diesel engines is referred to as Tier 2 (date range shown in chart 1). Major focus was on NOx, hydrocarbons (HC) and particulate matter (PM). PM reductions were as much as 25% on some engines.

Tier 3 for Doosan Equipment
Tier 3 standards applied to Doosan models with engines of more than 75 horsepower (shown in chart 1). Tier 3 focused on reducing NOx emissions roughly 39% for these machines.

How Did Tiers 1-3 Impact Doosan Equipment?
Doosan machines span a vast range of different horsepower levels. For example, the Doosan excavator line alone ranges from 51 to 463 horsepower. Understandably, changes to equipment varied considerably, depending on the size of engine used.


As a whole, major changes to Doosan equipment included turbo charging, improvements to the engine combustion system and use of high-pressure common rail fuel injection (HPCR) systems.

Interim Tier 4 (iT4) and Tier 4 (T4) for Doosan Equipment
iT4 compliancy deadlines for Doosan equipment started in 2008 (50-75 hp engines) and will continue for larger engines until 2012. T4 compliancy deadlines will span 2013-2015. Similar to previous emission tiers, further reductions to NOx and PM will be the main objective.

Chart 2

Engine SizeiT4 Compliancy DateT4 Compliancy DateNew Systems Needed for iT4 Compliance?New Systems Needed for T4 Compliance?
50-75 hpCompliant2013CompliantYes
75-100 hp20122015YesYes
100-175 hp20122015YesYes
175-300 hp20112014YesYes
300-600 hp20112014YesYes