Volvo Construction Equipment has received Tier-4 interim certification for its Volvo D11, D13 and D16 engines. The engines are built with ultra-high-pressure variable-fuel injection systems, cooled exhaust gas recirculation, precise variable-geometry turbo turbocharger controls, a new engine management system and an integrated exhaust after-treatment system, equipped with a particulate filter and thermal regenerator. The V-ACT system offers enhanced engine monitoring, greater control capabilities and higher torque. EGR lowers the amount of oxygen in the combustion chamber, reducing combustion peak temperatures. The after-treatment system reduces PM by 90 percent.