Sportec’s move to use a sports air filter and a newly programmed engine control in a 2010 Audi S4 Avant prodded the vehicle to get over the 400 PS mark with its 333 compressor-PS. The Swiss tuner applied its techniques to push the vehicle to get a full 425 PS rather than the standard 333 PS from its three litre V6 compressor.
Revising its electronics raised its torque to its maximum. So instead of 440, the maximum has been increased to 520 Nm. This boost is significant in the driving dynamics. The standard Audi S4 is capable of accelerating from a standstill to 100 km/h in 5.6 seconds but the Sportec RS425 can do this in only 5.2 seconds.
Top speed is unchanged as it is electronically limited at 250 km/h. But Sportec made other upgrades too. The vehicle was given a special sports silencer with four end pipes as there will be two pairs on either side. These generate a sportier sound. Braking power is assured with a braking system on the front axles that has been enlarged to 380 millimetres.
Meanwhile, Sportec reduced the chassis clearance as it fitted the vehicle with a suspension kit made shorter by a progressive 25 millimetres.
Furthermore, the Sportec RS425 was given a set of 9 x 20 inch large lightweight metal rims covered by 245/30 tires. The Audi S4 also got a diffuser at the rear and a spoiler at the front. These two items are built of carbon.