John Deere Power Systems will meet the Interim Tier 4/Stage III B off-highway emissions regulations by installing diesel oxidation catalysts (DOC)/diesel particulate filters in its Tier 3 PowerTech Plus engines.

The emissions regulations begin in 2011 and require engines of 174hp to reduce diesel particulates by 90 per cent and oxides of nitrogen by 50 per cent.

John Deere opted for the DOC technology because it is simpler, cheaper and has a proven track record.

The DOC unit has been created specifically for off-highway vehicles and carbon monoxide, hydrocarbons and some particulate matter are all reduced by a process of 'regeneration'.

John Deere decided not to use selective catalytic reduction (SCR) technologies because it requires vehicles to be fitted with a separate tank as well as an injection system.

It also uses urea which freezes and is not readily available in some parts of the world.

Source:

John Deere Power Systems Announces Interim Tier 4/Stage III B Technologies, 25/03/08
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