The standard power of your Audi A8 4.2 TDI 350hp vehicle is factory 350 hp / 800 nm. After Audi A8 chip tuning custom vehicle software, your vehicle will gain +50 hp / +150 nm additional power and reach a total power of 400 hp / 950 nm. Since there will be no change in the exhaust emission values of your vehicle, there will be no smoke in your vehicle.