For a car that???s always been known and marketed as the 911, Porsche???s timeless sportscar certainly has a lot of other numbers behind it. Let???s have a look at the internal numbering system, which differentiates between various 911 generations, to help clear things up a touch.

For twenty five years, everything was easy. The 911 type-delineation persisted throughout many production models from 1963 until 1989, including the venerable 911 Carrera RS from ???73 and ???74.

The first new 911 type came in 1975, when Porsche introduced a new flagship 911 ??? the 930. The 930 was the fastest production car available in Germany when it first rolled out of the factory doors, sporting a turbocharged, air-cooled, three litre flat six, which grew to a 3.3 by 1978.

Porsche???s 959, a new model entirely, hit the scene in 1986 and, in Sport configuration, was able to run a standing quarter mile in 11.9 seconds and go from a standstill to one hundred kilometres an hour in 3.7 seconds. A true supercar. Although it shares the family curves, retaining the basic shape of a 911, it isn???t a 911. It did, however, teach Porsche a few valuable lessons that would make their way into future 911s.

In 1989 911s became type 964s and inherited some of the innovation that went into building the Porsche 959. The 964 type arrived in the form of the four-wheel-drive Carrera 4 and sported a futuristic rear wing that would only rise up at high speeds. This made the car nice and slippery until the wing was required to produce downforce and increase stability at high speeds.

Next came one of the most desirable classic 911s ??? the 993, last of the air-cooled 911s. The turbo version arrived in 1995, featuring twin turbochargers which, when paired with the 3.6 litre motor, produced 300 kilowatts.?? Lovely.

Water was cool in 1998, and the 996 type 911 used it to replace the air that had been cooling 911s for the previous 35 years. The 996 also brought with it a new body shell and sleek modern styling, and introduced some modern classics, like the GT3, 996 Turbo and GT2. Later 996s received some small aesthetic alterations, giving them more of the curvaceous ??urbo??? look that we know and love.

And so we arrive at the two modern 911s: the current 997, introduced in 2005, and the upcoming 991. When designing the 997, Porsche went back to their stunning 993 for inspiration; incorporating, upgrading and innovating some of the modern technology and design of the 996, while sticking to the core values that make the 911 a brilliant driver’s car.

The 991 is an evolution of the 48 years of 911s that have come before it, incorporating the design lessons learned from the 996 and, in particular, the 997, and bringing the design and performance of the 911 into a new decade. We???ll learn more about it at the Frankfurt Motor Show later this month.

A breakdown of the various generations of 911, and their type number:

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• Porsche 911: 1963 to 1989
  
• Porsche 964: 1989 to 1993
  
• Porsche 993: 1993 to 1998
  
• Porsche 996: 1999 to 2005
  
• Porsche 997: 2005 to 2011
  
• Porsche 991: 2012 forward