Changing the name came down to what the company had on hand.
The latest addition to the Porsche Museum in Stuttgart, Germany, is a beautifully restored 901. In a new video, the company explains why a handful of cars wear this three-digit moniker rather than the far more recognizable 911 model name.
Like today, Peugeot's vehicles used three-digit model names in the early 1960s, for example the 203 and 403 at the time. Therefore, the French automaker believed that it held a trademark for automotive names with three numbers and a zero in the middle. Porsche had time to build 82 examples of the 901 before the Peugeot convinced the Germans to change the moniker. According to the video, Peugeot sent a "friendly but distinct letter" telling Porsche to pick different branding for the new sports coupe.
Gallery: Porsche 911 (901 No. 57)
Porsche came to a rather simple solution. It was already producing separate 9, 0, and 1 numerals to affix to the vehicles. Rather than coming up with a completely different name, the company simply replaced the 0 with an extra 1, and the result was the now iconic 911 moniker.
The newly restored 901 that went on display at the Porsche Museum was the 57th example to leave the factory. A TV crew discovered the car in an abandoned German barn in 2014. Porsche then acquired it and began the job of rejuvenating the rare vehicle. It'll be part of the special exhibit "911 (901 No. 57) – A Legend Takes Off" through April 8, 2018.
Among the few 901s, Porsche commissioned Karmann to build single convertible as a prototype. RM Sotheby's put this unique car up for auction in Paris in February 2017. It sold for 649,600 euros, which was significantly under the company's estimate of €850,000 and €1,000,000 (the equivalent of $900,000 to $1,060,000 at that time).
Source: Porsche via YouTube