A system and method of estimating a load bearing on a vehicle tire includes an inflation pressure measuring sensor attached to the tire for measuring a tire cavity inflation pressure level; and one or more piezofilm deformation measuring sensors mounted to one or both of the tire sidewalls. The deformation measuring sensor generates within the tire footprint a deformation signal having signal power level indicative of a level of sidewall deformation within the footprint contact patch. Power-to-load maps adjusted for tire inflation pressure are generated and stored for the tire, the maps correlating a range of load levels to a range of signal power levels whereby operatively enabling a load level to be identified for each signal power level on an inflation pressure adjusted basis.