The Audi S6 and S7 are now available with an ECU update developed by APR for the 4.0 TFSI engine. The V8 engine develops 420 HP and 406 lb-ft in its standard configuration, but with the ECU upgrade it can churn an extra 108 HP (at 553 HP) and 155 lb-ft (at 588 lb-ft) when running on regular 95 RON fuel. If you fill up the gas tank with 98 RON fuel, the engine develops an extra 125 HP (at 563 HP) and 187 lb-ft (627 lb-ft) of torque.
When using RON 104 fuel, the 4.0 TFSI V8 engine is able to push out an additional 138 HP (at 578 HP) and 198 lb-ft (635 lb-ft) of torque. Aside from this massive power bump, APR’s engineers have also made some improvements to how the cars accelerate and they also fiddled around with the launch control system.
Despite the significant power gain, fuel economy can be improved depending on driving style and the quality of the fuel used. APR will also raise the top speed limiter and they also offer a left foot braking feature.