Various types of hydrocarbon-based ionomer membranes have been proposed for application in fuel cells as an alternative to perfluoroalkylsulfonic acid (PFSA) membranes. The issue of chemical and mechanical degradation of this class of ionomer membranes and the combination thereof, especially under automotive operating conditions, has not been fully resolved at present. Here, we highlight key degradation mechanisms of hydrocarbon-based membranes in the fuel cell and identify necessary developments to mitigate radical induced membrane degradation and mechanical shortcomings of this class of ionomers that may enable them to compete with and, possibly, replace PFSA membranes. (C) The Author(s) 2018. Published by ECS.