The Scania HPI (High Pressure Injection) system minimises harmful emissions without imposing unnecessary restrictions on fast build-up of torque. This system is also highly fuel efficient because minute and infinitely variable adjustments in timing ensure precise delivery of fuel.

Back to basic mechanics
In many respects the Scania HPI unit injector is similar to traditional mechanical injectors that have been used for many years: Fuel is pressed into the combustion chamber at high pressure by a mechanical plunger that is driven by the engine’s camshaft. The innovation in this case is Time Pressure Metering. This approach uses a separate feed of fuel to the injector to better adjust the timing.

By making infinitely small variations in the volume of injection and the timing of fuel introduced into the injector, it is possible to gain precise control over the process and thus how it affects consumption and emissions.

More than an economic argument
In addition to the significant benefits of high torque, good economy and low emissions, Scania HPI offers other significant benefits: easy, low cost maintenance, lower noise levels and warm fuel.