Thought that the long-running push by regulators to clean up the exhausts of tractors and other farm machinery was nearly over? Then, think again, because it looks like Stage V (Tier 5) is set to be the next set of exhaust cleanliness hoops that engine manufacturers will have to jump through to meet EU standards.

The latest set of proposals are being discussed with industry stakeholders and, if agreed upon, could be adopted by the European Commission by the end of 2015 and introduced between 2019 and 2021, according to industry sources.

See also: How will the emissions regs affect farmers?

As the latest round of emissions legislation nears completion, with most manufacturers having launched Stage IV Final compliant engines, having another set of emissions legislation to meet is somewhat of a blow to the industry.

Speaking at the Integer Emissions Summit in Dusseldorf in June, senior scientist at the Joint Research Centre of the European Commission Dr Adolfo Perujo hinted that new Stage V emission limits would be more closely aligned to current on-road emissions targets.

Engine makers such as Italian company FPT have also suggested that new regs will target particulate levels for engines between 19kW and 560kW (25hp to 750hp), increasing the requirement for diesel particulate filter technology.

Proposals are for a reduction in Particulate Matter (PM) from 0.025g/kWh to 0.015g/kWh.

What does this all mean for farmers? More expensive engines and new ranges of tractors being launched with little new apart from the block beneath the bonnet.