Tractions were never fitted with a Revolution Counter or Tachometer. These instruments could only be found on sports cars and the Traction Avant was definitely not a sports car. Nevertheless it can be important to know the engine revolutions (RPM) at a given speed of the vehicle. People used to driving a Traction will know that the torque of the engine is better in the medium to higher RPM range -as a rule of thumb: around 2.500-3.000 RPM. Particularly in mountainous conditions it can be helpful to know when to downshift to get your engine back into the best RPM/torque range. Fortunately, data are available from Citroën that allow us to calculate RPM and vehicle speeds in any gear. For the Traction Avant, the so-called "V-1000" is known for both the 4 and the 6 cylinder models. That is the vehicle speed (in km/h) in top gear at 1000 engine RPM. For a "standard" 4 cylinder this value is 27,80 km/h, whereas for the 15-Six the V1000 value is 32,00 km/h. Based on those values and the reduction ratios for 2nd gear on both types, vehicle speeds and engine RPM can be calculated across the entire range, from idling to full throttle and anything in between.

 

The attached tables show combinations of engine RPM and vehicle speeds for a 4 cylinder as well as a 6 cylinder Traction Avant. The information at the top of the tables is important: the tables are based on "standard" gearboxes, differentials and tyre sizes. For Tractions with different tyre sizes like the 11 Familiale/Commerciale and the 15-Hydraulique the values will dioffer slightly. The same applies if your pinion/crown wheel ratio differs, like on the special "mountain" gearbox for the 4 cylinder which has a 8x31 ratio, or the opposite: a "longer" ratio -which is sometimes installed on both 4 and 6 cylinder cars. For those non-standard differentials the V-1000 value will differ quite considerably.
The tables can be downloaded and printed or stored onto your tablet or smartphone.

You can use the tables in two different ways:

Blue columns: engine RPM is the input, vehicle speed is the output
Red columns: vehicle speed is the input, engine RPM is the output.