29 April 2002: The ‘1-litre’ car recently showcased by Volkswagen, which has shattered world vehicle economy records, displays a host of innovative touches. However, the most accessible of the technologies displayed by the prototype is its high-pressure Unit Injector System (UIS) by Bosch.

The car could not generate its sensationally low fuel consumption of 0.99l per 100km (285 mpg) without the extremely high injection pressures of more than 2000 bar created by the Bosch UIS, which creates an ultra-fine spray of fuel in the combustion chamber to generate particularly effective combustion.

Fuel is injected into the combustion chamber through a six-hole injector nozzle, with high-precision solenoid valve control guaranteeing exact measurement and delivery of fuel, as well as precise injection timing. Preliminary injection is also used to reduce combustion noise.

The Bosch UIS used in the 1- litre VW also guarantees economical consumption and low emissions in standard production vehicles. The Volkswagen Lupo 3L TDI and Audi A2 3L 1.2 TDI, for example, stretch 3.0 litres of diesel fuel over 100 kilometres and were the first diesel vehicles to comply with the strict ‘Euro IV’ emission limits.

The potential of UIS by Bosch is also becoming apparent in larger vehicles. For example the Volkswagen Golf TDI and Bora TDI, with their new 74 kW engines also comply with the emission limits laid down in accordance with ‘Euro IV’.

©2002irishcar.com