I tow both the R29 and R31 sedan and bridge models for testing. I travel on freeways and city streets in order to access the water, I will say they both tow about the same. Depending on if the R31 is a bridge or not it can tow different with the little added height of the bridge. The R31 is around 2000-2500lbs more than the R29 sedan vs. bridge so there is a little added weight. Hope this helps.