Performance Measurement

All performance measurement is not the same

For us, tuning at the highest level does not just mean efficiency and simultaneous engine protection, but also the manufacture of high-quality, comprehensively tested products. As a serious vehicle tuner, the confidence of our customers is always our highest priority. Therefore, honesty with test results and transparent measurement processes – especially when it comes to performance measurement – are a particular concern for us.

How is engine performance measured?
  • When we speak of a vehicle’s performance, we are referring to the corrected power. This is the power that the engine transfers to the crankshaft.
  • Since the measurement at the crankshaft of an engine which is installed in a vehicle is not practical, the engine power is generally measured on a dynometer. Here, the so-called wheel power is measured, that is, the power that the wheels transfer to the road.
  • Due to the friction from the transmission, drive shafts, differential and wheels, wheel power is always less than corrected power. In order to be able to quantify these losses, in addition to wheel power, the drag power of the drive train is measured on the dynometer. In this case, the vehicle is measured in a declutched state. Since a performance upgrade has very little or no influence on the drag power, there should only be the tiniest deviation between the standard and the tuned vehicle.
  • Finally, the previously calculated result is adjusted by the standard correction factor, which is calculated depending on the standard (in accordance with EEC, DIN or ISO) from the ambient data such as temperature and air pressure. 

The formula for the corrected power is as follows:

Corrected power = (wheel power + drag power) x standard correction factor

Example of performance measurement on an RS 6 with ABT Power
Influencing factors on performance and performance measurement

In principle, all dynometer designs (e.g. twin roller vs. single roller) should provide almost identical results. However, deviations in the implementation of performance measurements such as measuring period, ambient temperature, speed and much more can cause inconsistencies. Our engineers use exclusively a MAHA single roller dynometer and the measurement procedure is always carried in accordance with the defined standards.

However, performance measurement does not only depend on the type of measurement, the results are also influenced by other factors. In this way, among other things, fuel also has an influence on engine performance. For spark-ignition engines with ABT performance upgrades, we recommend that premium fuel with the octane value specified in the data sheet (RON 98/AKI93 or RONZ 102/AKI 95) is always used. This not only gives the best power characteristics, but is also an important factor with regard to the longevity of the engine.

Similarly, operational performance also influences engine performance. At ABT, only ‘run-in’ vehicles with mileage of over 3,000 km are tested.

Indicators of unreliable performance measurement are, among other things, drag power that is 20 or 30% (depending on dynamometer design) higher than the standard performance as well as slippage or correction figures that are greater than 5%.

As the official tuner of vehicles from the VW Group, we fundamentally use measuring procedures that are recognised as standards for vehicle manufacturers. Our dynometer is regularly serviced and calibrated by the manufacturer and is also TÜV-tested. Only by utilising reliable and qualified measurement methods are we able to continue to ensure our customers that all of our products are not only TÜV-certified, but also guarantee a long durability.