Gasket sealing performance of a manifold is traditionally characterized either by pressure distribution on flange face or line loads on gasket beads. These readings are sometimes susceptible to error due to complex contact algorithms or lack of reliable gasket data. In addition, they are difficult to correlate, particularly in the case of log-type manifolds. Here, a different approach for assessing gasket sealing performance of exhaust manifolds is presented based on overall manifold distortion under thermo-mechanical loading. Current technical paper describes the methodology used and presents a validation work.