Abstract: An onboard weighing device for a vehicle is provided which allows the weight sensor to be positioned off-center to accommodate centrally positioned vehicle components while still maintaining the accuracy of the average weight determined by the sensor. The weight sensor is mounted between a fixed point on the vehicle and a center averaging arm. The ends of the averaging arm are coupled with mounting arms which are in turn coupled with spaced apart portions of the suspension. Alternatively, the mounting arms can be coupled with the tandem axles or the drive differentials for those axles. The mounting arms are of different lengths so that the midpoint between the ends of the mounting arms coincides with the mounting point of the weight sensor on the center averaging arm. This results in the effective distance between the sensor and the load points on the axles being substantially equal despite the spacing of the sensor from the true centerline between the load points.