The 2013 BMW 520i is known for its comfort, refinement, and smooth performance—but there's plenty of potential waiting to be unlocked. With a VAITRIX Stage 1 performance upgrade, this BMW 520i received a significant boost in power and torque. From 184 HP to 252.5 HP The factory BMW 520i produced approximately 184 HP and 27.5 kgm of torque. After the VAITRIX Stage 1 upgrade, those figures increased to an impressive 252.5 HP and 33.4 kgm of torque. That's a gain of 68.5 HP and