French army website is not a reliable source since a lot of the numbers are cooked. Same case with how the Bundeswehr website is not always reliable.
Regarding the brochure @FurinaBestArchon has attached above, it is from the early 2000s (even then GIAT would understate the performance of their vehicles). If we refer to this display at Eurosatory 2022, it states that the off-road speed of the Leclerc (note that the XLR drive train is the same as on previous Leclercs) is 72 km/h.
Now look at the Eurasatory 2022 display for the 2A7 and note how it says the on-road speed is 60 km/h:
It makes the distinction between on-road and off-road speed. Now if we refer to the testimony of a Leclerc captain:
“The tank alone weighs nearly 57 tons and can reach speeds of 70 km/h in all terrain and 90 km/h on the road”
Similarly, there is also a document from the French army which states a top speed of 90 km/h (which I’ve attached above somewhere).
Nevermind all the other secondary sources that state a top speed of 90 km/h.
And here, for shits and giggles… a Leclerc travelling at 80 km/h to demonstrate the brakes. Earlier in the video, the Leclerc crewman states they will be travelling at 80 km/h: