mi = The technically permissible maximum mass on the axle designated `` i '' , where `` i '' varies from 1 to the total number of axles of the vehicle ; uj = The technically permissible maximum mass on the solo axle or group of axles designated `` j '' , where `` j '' varies from 1 to the total number of solo axles and groups of axles ; TM = The technically permissible maximum towable mass ; and MC = The technically permissible maximum laden mass of the combination .