The rolling resistance of China 45HP FARM WHEEL TRACTOR is mainly due to the deformation of tires and soil. Under the heavy pressure of the four-wheel drive tractor, the tires are flattened and the soil is compacted. During the rolling process of the wheel, each part of the tire that contacts the ground along the circumference direction will be flattened and deformed subsequently, while the earth pressure in front of the wheel will deform under the earth pressure to form wheel ruts, that is, rolling resistance will prevent the wheel from rolling forward. There are many factors affecting the rolling resistance, mainly related to the ground firmness and the moisture content in the vertical load. For the same four-wheel drive tractor, if the ground conditions are different, its rolling resistance is also different. For example, when driving on asphalt cement or dry and hard ground, the rolling resistance is small, but the traction of the four-wheel drive tractor is large. Under the same use conditions, if the weight added to the tire is large, the vertical deformation of the soil mass is also large, and the rolling resistance is also large. In general, reducing the deformation of the tire itself and the deformation of the soil in the vertical direction is conducive to reducing the rolling resistance. If the Farm Wheel Tractors are running on the soft ground, use low pressure tires to increase the tire support area, which can reduce the vertical deformation of the soil, reduce the rolling resistance, and thus improve the traction. As the four-wheel drive tractor is mainly used for field operation and runs on soft ground to reduce the vertical deformation of soil, the four-wheel drive tractor generally uses low pressure tires, and the same reason is that the widened tires are used. In our business, we should pay attention to the differences between low pressure tires, widened tires and high pressure tires in use.