Hi , I recently bought a 911 S 1973, and I have some questions related with oil,.......!!!

1) Which the working temperature, let's say at 60-70 mph
2) which is considered like normal oil comsuption by 600 miles (in liters please!!!....I am sorry I am european!!)
3) And last, mineral or Synthetic??

Thanks all, I wait for your answer cause I am a bit worried