A wheeled forestry tractors design, such as that for a wheel feller-buncher or a site prep tractor, is disclosed. The disclosed design includes a front axle connected to a rear axle by an articulated chassis. A cab is supported between and above the front and rear axles by the chassis. An engine and a hydraulic system are mounted opposite the rear axle from the cab and in a side-by-side relationship with the engine being aligned transversely with respect to the chassis and parallel to the rear axle. The engine is mounted transversely or parallel with respect to the rear axle and slightly behind the rear axle to improve the weight distribution between the front and rear axles or between the front and rear frames. By mounting the engine transversely and on one side of the rear of the tractor and the hydraulic system on the other side of the tractor in combination with placing the fuel tank in alignment with the engine and the oil tank in alignment with the hydraulic system, improved left to right weight distribution is also achieved.