HMM: Volkswagen Mission Efficiency Concept First Look: The Most Efficient EV Yet. “Efficiency is an unheard of 9 miles per kWh, and with a 54.9-kWh battery, range comes in at 514.5 miles for a battery slightly more than half the size of the EQXX’s and and a zero to 62 mph time of 9 seconds. (Doubling the size of the battery would not necessarily double the range as it would also increase the weight substantially, and likely the size of the vehicle.) Production EVs today struggle to exceed 4 miles per kWh, with EV maker Lucid publicly declaring its goal of a 5-miles-per-kWh production car in the future.”