A vehicle having a suspension comprising a double acting ram (13, 14, 17, 18) connecting each wheel (1, 2, 3, 4) independently to the body (5) of the vehicle, each ram (13, 14, 17, 18) having respective first (13a, 14a, 17a, 18a) and second (13b, 14b, 17b, 18b) chambers that vary in volume as the wheels move relative to the vehicle body (5). Each front wheel ram (13, 18) is connected to the diagonally opposite rear wheel ram (14, 17) by a respective pair of conduits (8, 10) and (8a, 10a) arranged so the first chamber (13a, 18a) of one wheel is connected to the second chamber (14b, 17b) of the other wheel. Each first and second chamber and the conduits connected thereto are filled with fluid and independent of external fluid and pressure sources. Diagonal interconnection of the front and rear rams minimizes roll movement in a lateral direction and pitch movement in the longitudinal direction of the vehicle.