This paper presents a method to evaluate vehicle static inertial parameters and dynamic states based on measured wheel forces. By combining a traditional vehicle model with the sensed forces, a simple observer may be devised to compute at first vehicle mass inertial properties; then, using also the other information currently available on passenger cars, the full vehicle state can be estimated. The estimation procedure and algorithms are validated with a nonlinear vehicle model: the results obtained from several simulation examples show that estimates of the inertial parameters generally have small relative errors; moreover also the estimates of the dynamic states appear promising.