In this paper the comfort sensitivity to the variation of the inertia parameters is studied. For the theoretical approach, two computational models that predict the comfort response of a vehicle are developed and verified. These models are used to study the effect of a change on the inertial properties of the car on its comfort response. The models are developed on a commercial multi-body package and also implementing handwritten equations with a numerical integration algorithm. The influence of the inertial properties on comfort is also experimentally studied. Both approaches use two different road patterns as input generating a roll and pitch excitation. An allowed uncertainty on the inertia properties is proposed, based on the sensitivity to those properties.