You should only undertake the modification of the speedometer if you are confident with electrics. Please also note that there is more than one type of module available, so fitting may vary. These instructions were kindly provided by Michael Herrmann.

Twingo's digital display works by counting electrical pulses from a sensor mounted in the gearbox, and converting the number of these pulses per second into the car's speed in kilometres per hour.

A small module fitted between the sensor and the speedo unit divides the number of pulses by 1.61, thus the figure received by the speedo is in miles (see wiring diagram, fig1).

Modification Instructions
Before starting, switch on the car's power and record the current kilometre reading.

Disconnect the battery, then remove the upper section of the dashboard and the display unit (fig2), both of which are fitted with three size-15 Torx screws.

Unclip the cable from the rear of the unit, and locate the green, yellow, and black wires (fig3). Prepare these three wires as shown in fig4: yellow is the power supply and black is earth (ground), and the module's power and earth wires need to be tapped into here (fig5).

In order to ensure a secure and reliable connection, it is advisable that the module's power and earth cables be soldered to the existing power and Earth wiring, rather than just being taped on.

The green wire carries the pulse from the gearbox sensor. This must be cut, and the two ends connected to the signal input and output ports in the module. With the module correctly fitted, ensure that all three wires are properly insulated in order to prevent shorting-out the module and speed, then re-fit the unit to its dashboard mounting.

Finally, before re-fitting the dashboard top, use black tape to blank of the K's on the speedometer and odometer displays, to show that the reading is now miles as opposed to kilometres.

You may also want to reset the odometer. It is wise to ensure that a note is made of the recorded distance before resetting and/or driving the vehicle, so that your Twingo's service history has a note of the full details of the conversion, and the reason for the odometer being interfered with. When selling any car, an accurate history is always important to potential buyers.

fig1: Wiring diagram of completed comversion

fig2: Speedo unit removed from mounting position

fig3: Speedo cable identifying green, yellow, and black wires

fig4: Preparation of wires for module installation

fig5: Guide to wiring adaptation