Some forums managed to dig out some information we sat on for a while, so we decided to share what we have known since last year. In summer of 2012, BMW built 30 F80 M3 test vehicles with a new engine, codename S55. The engine as we mentioned many times before is an inline-six turbocharged developed by M engineers but based on the N55 unit.

The prototypes were built to be tested in all kind of driving conditions and to determine their power potential, one that our sources continue to say it will fall somewhere between 410 and 450 horsepower. It is widely known that BMW is famous for publishing lower horsepower numbers that the engine’s potential, so anything is possible with the M3 and M4.

This latest tidbit of information was found in a BMW VIN registered with the UK authorities and confirms what we have known: inline six and above 400 hp (415 to be exact). Another interesting reveal is the displacement, 3.0 liter versus a widely rumored 3.2 liter unit.

Engine code S55 for next BMW M3 / M4

Since the car is most likely still in the testing phase, the horsepower number is not set in stone and could change until launch time.

Some BMW fans might be disappointed by the power figure, but as Dr. Friedrich Nitschke, BMW M CEO, told us exclusively last year, the M division focused on weight reduction techniques for the new M3 and M4, which implicitly will offer better performance than the current E90/E92 models.

BMWBLOG: What are some of the things that M does to keep a lower weight of future cars?

Dr. Nitschke: This is one of the most important things for us: reducing weight. In the new M5 and M6, we reduced the weight quite a bit, but dramatically weight savings will be seen in the new M3. We are using not only parts made out of aluminum, but we are also at the the front of our industry to use carbon fiber across many models. We will bring additional parts made out of carbon fiber.

Even though we initially believed that the M3 will be present in Geneva in March, we are now inclined to believe that BMW will save the big reveal for their home show in Frankfurt, a far better and more imposing venue to reveal one of their flagship models.

Stay tuned in the next few weeks for more information as testing approaches its final stages!

By Horatiu Boeriu. Read Bio