Increasingly basic formulations of automotive lubricants have required that new heat- and oil- resistant elastomers be developed. The reactivity of VF2-based elastomers in solution is examined in an NMR-monitored study and compared to that of VF2-free fluoroelastomers. It was found that that a VF2-free elastomer based on TFE and P that contains curesite levels of 3,3,3-trifluoropropene responds very well to basic vulcanization with bisphenols and yet affords outstanding resistance toward base in service and in competitive dehydrofluorination studies in solution. This desirable behavior is attributed to the high reactivity of the curesite monomer and to its limited concentration.