The injectors of the original 4-cylinder 1.9l TDI engines with 90hp usually have a hole size of 0.184mm and the engines with 110hp 0.205mm. These nozzles have a hole size of 0.250mm. The larger channels allow more fuel to be injected in the same amount of time. With an otherwise unchanged engine, this results in an increase in performance between 25hp and 80hp. Without adjustment of the control unit software, the nozzles act like a moderately powerful tuning box, but without the disadvantages such as excessively long injection times or distortion of the engine parameters. The soot emissions are only slightly visible in the 90hp engines; the 110hp variants run as standard with enough excess air so that there is no visible soot formation. For the 90 HP engines it is definitely recommended.
