The current generation of tractor engines are at Stage IIIB or US Tier 4, while the next generation are facing an even more stringent Stage IV or US Tier 4 Final target with even lower levels of exhaust emissions.

Last week, at the German Bauma construction machinery show, JCB, one of the newer entries to the engine business, announced its new Tier 4 Final engine strategy for its Ecomax engines. The company said that the new engines will give a 5% fuel saving. The other important feature is that these engines use selective catalytic reduction (SCR) technology, which means using AdBlue, but at lower levels than in other engines.

JCB said that it has re-calibrated the Ecomax engine to achieve the reduced emissions requirement, resulting in a further 5% fuel saving over existing models. JCB is using what it calls a compact SCR solution on engines above 55kW (74hp). This SCR system will be incorporated into a single exhaust muffler, in many cases replacing the existing exhaust and providing what it calls a ‘one can’ solution, delivering the same overall dimensions for machine designers.

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JCB claims that its SCR system will use a 2% to 3% ratio of exhaust additive to fuel, as the engine is already providing clean exhaust gases. JCB officials say that this is in contrast to many existing SCR systems that use a 6% or 7% ratio, but they were quick to point out that ratio numbers depend on machine application.

JCB has engineered a new, smaller mixing system for the SCR, which offers a reduced exhaust flow distance between the engine and the catalyst. JCB claims that the engine package, unlike many competitors, can be installed in existing machinery without bulky alterations to bodywork.

As with all Tier 4 Final engines, low-ash lubricating oils will be required, along with an exhaust additive filter. However, there will be no additional maintenance required on the JCB Ecomax engine, including no costly cleaning or replacement of exhaust filters.

As with the Stage IIIB/Tier 4 Interim Ecomax engine, JCB claims that it will be possible to de-tier the Tier 4 Final range, to allow customers to sell used equipment in less regulated countries. All JCB dealers worldwide will have the technology to remove the SCR kit, reduce the fuel injection pressures and re-calibrate the engine.