There's no reason. 14-50 will charge faster but you'd have to put in new wiring, outlet, breaker, etc. and with the current mobile connector, it maxes out at 32 amps. Older mobile connectors could charge at up to 40 amps. That would be faster than the 24 amps you'll get on a 14-30 outlet but if you don't need the faster charging, it's probably not worth the expense. You just need to buy the 14-30 adapter from Tesla.