View Single Post
Old 08-22-2014, 01:26 AM   #19 (permalink)
Ryland
Master EcoModder
 
Ryland's Avatar
 
Join Date: Jan 2008
Location: Western Wisconsin
Posts: 3,903

honda cb125 - '74 Honda CB 125 S1
90 day: 79.71 mpg (US)

green wedge - '81 Commuter Vehicles Inc. Commuti-Car

Blue VX - '93 Honda Civic VX
Thanks: 867
Thanked 434 Times in 354 Posts
Quote:
Originally Posted by xntrx View Post
I wonder if that is under acceleration or at constant speed, and fixed or variable pitch. A conventional drive will lose between 10-25% from friction and pumping (auto), so that's not too terrible. .
That 59% is in ideal conditions as I understand it, the mathematical max that you can get before air just moves around the prop.

With a regular drive-line you can get 98% with a well designed gear box or chain drive, the rest of it, tires and bearings are going to be the same because you have to have those to have wheels on the ground.
  Reply With Quote