During the production of the 6 volt M201 a number of technical improvements were made but the greatest single advance was the introduction of the M201 24 volt model that replaced it though the exact point at which this happened during 1960 is difficult to determine. From army manuals it would appear that the 24 volt model was approved in April 1959 and manufacture began in the mid 1960s. All jeeps up to Nº 6966 (covered by army manual MAT 3541 / CAT 4-584) were certainly 6 volt, Nº 08829 was certainly 6 volt and, according to Army manual MAT 3541, all jeeps after no. Nº 8961 were 24 volt.

 

 

 

Under the bonnet two twelve volt batteries replaced the old single six volt battery and the ignition and charging systems were completely screened to suppress radio interference. To make space for this the air filter was relocated to the front of the engine bay.

 

photo: Etorre Galli

 

photo: Christophe Muller

 

The screened spark plugs and leads can be clearly seen in the above photo as can the Solex carburettor that replaced the war time Carters carburettor fitted to the 6 volt model. Other features can be gleaned from the publicity brochure below (translated by JLM).
 

 

In a way the revised 24 volt design with its dashboard mounted start button, instruments by Jaeger, aerial mounts on each rear corner, later style blackout light on the front wing etc. became the jeep everyone today instantly recognises as a 'Hotchkiss'. This is not just because about nineteen thousand of the 24 volt M201 model were made but because most of the original 6 volt Hotchkiss M201s, ITM jeeps, and even some MBs & GPWs belonging to the army were all rebuilt to this new standard during the 1960s and 1970s by ERGM at La Maltournée.   Although the aerial mountings are listed as a 1960 improvement a number of photographs used to illustrate the new model show a 24 volt jeep without these. It is possible that some of the stock photos like the one below  from a Satory exhibition guide were actually of a prototype produced by Hotchkiss.
 

 

Strangely, army manuals for the M201 24 volt used rebuilt jeeps for illustration purposes even though they would have actually contained a 'hotch-potch' of WW2 and Hotchkiss parts. The examples below are from MAT 2835.

 

The official data shows that, both empty and fully equipped, the 24 volt M201 was heavier than its predecessor.

Obviously the weights and characteristics of ERGM modified models varied considerably. The SS10 launcher was probably both the longest at 3.52 metres and widest at 1.90 metres.

I am grateful to J-L Martin for providing copies of the various official data sheets used or referred to on this page.