APR is pleased to present the ultimate engine control unit (ECU) upgrade for the C7.5 Audi S6 and S7 4.0 TFSI V8. The APR Stage I ECU Upgrade gives you higher peak numbers of 574 HP/638 FT-LBS on 93 (R+M)/2 octane and up to 597 HP/668 FT-LBS on 100 (R+M)/2 octane race fuel! As much as 186 HP and 243 FT-LBS of torque are available through the power band! APR’s latest ECU Upgrade is fully loaded with APR’s EMCS Program Switching and is compatible with APR Mobile. To read more, visit our product page.