The electric SUV equipped with the Max pack will get an EPA-estimated 400 miles of range. But the pack will also cost $16,000 more than the standard range battery, which only goes 260 miles on a single charge. Rivian customers can select Max pack for the Dual-Motor AWD models including performance, but not for the quad-motor version. An R1S with Max pack starts at $94,000 and Rivian says deliveries begin this fall.