It wouldn't hurt anything to run in MM all the time, but there is no long term benefit either. Mountain Mode will kill your efficiency and gas mileage too. It's much cheaper and efficient to charge your Volt with an EVSE than to charge it using MM. Plus, switching to MM every time you start the vehicle will wear out the Mode switch. Many people who drive in Sport mode all the time have found this to be true.Slightly different scenario - matches the thread title. I moved into a condo rental that lacks any access to at home charging (my state has a law that entitles units to establish separate metering for their assigned parking, but I'm a renter). My employer also has zero outlets that I can use for even L1 charging. I occasionally use free L2 charging ~1mi from my garage, but typically am driving in CS/normal mode for the last ~10 months.
Any advice on whether there should be a long term benefit to keeping the car in mountain mode (MM) to maintain a ~45% SOC vs. the ~20-30% SOC in CS/normal? My 2013 Volt with 63K miles still has experienced minimal operational (~<5%) range degradation. I believe the battery would be best served kept at the MM SOC vs. the low end normal mode. Anyone have any input? I haven't seen this specific question on optimal gas-only operation for vehicle longevity, thanks!