EM27/SUNs are portable Fourier Transform Spectrometers that are being widely used to constrain urban greenhouse gas emissions. On a six week long campaign in summer 2018, the EM27/SUNs from University of Toronto were taken on a road trip to TCCON stations across North America to better understand the accuracy, precision and durability of the instruments as they have been moved from one site to another. In this talk, the preliminary results of this road trip will be presented.