On Tuesday and Wednesday at Silverstone, the 2006 season Mercedes-Benz Formula One engine was tested on the race track for the first time. According to the rules, it is a V8 engine with a capacity of 2.4 litres. Until the end of the 2005 season teams are using three-litre V10 engines. The current rules have been in force since the beginning of 1995.

Pedro de la Rosa was at the wheel of the interim Team McLaren Mercedes MP4-20B, a modified version of the 2005 race car, which has been adjusted to fit the new engine. Pedro completed 38 laps on Tuesday and 40 laps on Wednesday and achieved a best time of 1:22.974. Fernando Alonso in a Renault with V10 engine posted the fastest lap of the test with a 1:17.018.

The Mercedes-Benz V8 engine's debut came almost exactly three months after the first dyno run. Since that day the engine has completed a couple of thousand test kilometres on the dyno. The new V8 engine generation will have about 200 BHP less than the current V10 engines.

The new V8 Formula One engine FO 108S has been designed and built from scratch. The new engine rules place tighter restrictions on the manufacturers than before. Mandatory are: the V-angle of the cylinders (90 degrees) and the use of a maximum of two inlet and exhaust valves each (until now the rules have stated only the number of cylinders and a limit of five valves); an engine minimum weight of 95 kilograms; a maximum cylinder bore of 98 millimetres; the position of the engine's centre of gravity. Alloys for the manufacturing of engine components are also defined exactly. The biggest challenge for the engineers was and still is the vibrations which are completely different from the V10.

Work on the new engine began in the autumn of 2004 when a team of engineers drew up the first concepts. The design process lasted from Christmas to spring, a period during which the engineers also built one-cylinder models to test pistons, connecting rods and valve drives.

The V8 engine will also significantly influence the design of the Team McLaren Mercedes MP4-21 for the 2006 season. The V8 is smaller than the V10 and the new engine also needs less air than before. Therefore there will accordingly be significant modifications to the aerodynamics for next year's car. In addition ExxonMobil has developed a new fuel and lubricant.

Pedro de la Rosa: "The last two days of testing have gone well and we are on schedule with the development programme. There is obviously a big difference in power between the Mercedes-Benz V10 and the V8, and therefore I had to adjust my driving style. In between runs over the last couple of days, the engineers have been analysing the data and making changes to the car. It is positive that we were testing with the new engine without problems and long delays. During this test we have also been looking at the difference in vibration between the Mercedes-Benz V10 and V8 engines; however we didn't find anything we had not expected."

Norbert Haug, Vice President Mercedes-Benz Motorsport: "We had an uneventful track debut with our new V8 engine. With Pedro de la Rosa at the wheel we gained first basic experiences with the new engine on a race circuit and we completed our programme as planned. The data we collected during over 400 test kilometres will be analysed at Mercedes-Benz in Brixworth and will help us to develop the engine further as planned. The première was OK and everything goes exactly according to the plan we have set for ourselves."