I found this link
http://www.clubferdinand.us/cf-why-porsche.htm
70% of all Porsches ever produced since the company began production in 1948 are still in use.
You will find more bearing area, big-ends and mains for each liter of displacement in a 911 engine than in any other engine in production today. It’s an obscure technical point, but a telling one; indicating Stuttgart’s commitment to combining mechanical strength, accessible performance and glorious precision. You simply can’t buy a more robust high performance automobile. - Don Vorderman