Long Range Plus was never rated at 376, 371 was the best factory rating, which was the final two or three months of production only, for best case, perfect conditions, brand new battery, 20" wheels, no wind, no rain, one occupant, yada. Your car was most likely rated for 351 new. If it's showing 317 at 100%, it's still got as much range as a brand new Performance did. Chill. And if you want forum help, maybe post more information next time, like how many miles are on the car, or when it was built, or literally anything else