View Single Post
Old 07-10-2011, 08:58 PM   #4 (permalink)
Frank Lee
(:
 
Frank Lee's Avatar
 
Join Date: Jan 2008
Location: up north
Posts: 12,762

Blue - '93 Ford Tempo
Last 3: 27.29 mpg (US)

F150 - '94 Ford F150 XLT 4x4
90 day: 18.5 mpg (US)

Sport Coupe - '92 Ford Tempo GL
Last 3: 69.62 mpg (US)

ShWing! - '82 honda gold wing Interstate
90 day: 33.65 mpg (US)

Moon Unit - '98 Mercury Sable LX Wagon
90 day: 21.24 mpg (US)
Thanks: 1,585
Thanked 3,555 Times in 2,218 Posts
Quote:
Originally Posted by Ryland View Post
I haven't seen an alternator with a fan on it for years, so if your field windings are turned off then the only drag on the alternator are the carbon brushes, the bearings and the rotor, adding a clutch you will be adding another set of bearings, more rotating weight and more air drag.
Oh, they still have fans; they've just moved inside the housing (probably for noise reduction). Except for the liquid cooled ones.

The only potential savings I see from a clutched alternator are from not spinning a cooling fan. The added drag from the clutch itself may cancel out even that meager benefit.
__________________


  Reply With Quote