It all depends on how you drive, but look at around 35 to 40 mpg.
go to: www.goldwingdocs.com
Water cooled.
The 1100 has what is refered to as a wet clutch. The same oil that is used for the motor oil is used for the transmission. Because of this it is very important to use oil that is labeled "Wet Clutch Compatable". You can get this through your Honda dealer or motorcycle shop.
Honda 10w40 works well
What model?
Follow the lower rad. hose. Its in there. Have to remove the rad.
21 psi
The standard comes with no extra equipment, fairing or side bags. The interstate is a full dress right from Honda.
Manual for the 1979-81 Honda Goldwing 1100 states "inlet 0.1mm, exhaust 0.13mm" hope that helps, bye.
Front tire: 110/90-19Rear tire: 130/90-17
Good idea to check the battery. Might need to be charged, or changed.
Not very much in today's economy. That is a shame because it is a nice bike!