Current trend on engine downsizing forces engine manufacturers to contemplate powertrains with more than one boosting device. The presence of these devices leads to complex 1-D engine models which rely on performance maps provided by turbo/supercharger manufacturers. So far, no detailed analysis has been carried out to understand how these maps affect engine performance simulation. As part of the UltraBoost project (65% gasoline engine downsizing), Imperial College tested the boosting components of a turbo-super configuration. The acquired data were used to assess the effectiveness of 1-D engine performance prediction and to contemplate the opportunity to exploit the boosting system and use it as engine charge air cooler in the form of an expander.