text: http://www.172guide.com/models/172P-81.htm
  Maximum Useful Load:
      Skyhawk
      Skyhawk II	
  993 Pounds
  967 Pounds
  Baggage Allowance:	120 Pounds           
   
  flown many 172's with four people  unless the people weigh more than average and they pack too much gear four people is not overloading