This bug/oversight affects the BRDM-2 (all variants), the British MRAPs, and the British Coyote and Jackal
The Real-life top speed, on road, of the BRDM-2 is 100 km/h. (Source: Army Recognition.com). The British MRAPs can achieve 105 km/h, both the 4x4 and 6x6 (Source: Military.com), and the Jackal and Coyote can reach 120 km/h (Source: Army Recognition)
In the VR Terrain, the BRDM tops out at 70 km/h, while the British MRAPs top out at 85 and the Jackal and Coyote at 83.
This is inconsistent with other wheeled armor, all of which meet or exceed their listed IRL top speeds (RG-31, Dingo, BTR-60, Stryker, LAV, BTR-90)