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Old 08-21-2008, 11:12 AM   #7 (permalink)
johnmyster
EcoModding Lurker
 
Join Date: Aug 2008
Location: Virginia
Posts: 87

Brown Bus - '98 GMC Sonoma X-Cab SLS
90 day: 31.37 mpg (US)
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Quote:
Originally Posted by Daox View Post
From what I've read, alternators are only about 50-60% efficient
I've seen those numbers too, but I think they're worst case scenarios. At full load, the switching diodes (rectifiers) get really hot, and become heavily loaded. My gut electronics feeling is that they'll be more efficient at typical loads.

Our trucks have 100 amp alternators. Little to no A/C, power/heated seats, big stereos, navigation, etc. Only one tail light on each side. Single headlights. No foglights. No rear window defrosters. S10 owners usually get good life out of their alternators compared to Buick/Olds drivers. Same alternator, but vehicles with more goodies, and drivers that like to use those goodies. I knew an olds driver who killed a 120 amp alt every summer. AC on max all the time fried the rectifier every single summer. I gander that our alternators are generally not hard pressed and can squeak out a more efficient living.

I suppose most of my driving is long highway trips. 1 or 2 hp saved doesn't sound like much compared to the 50 whp or so it takes to keep me going down the road. Maybe, but 10% is still a lot. Enough to make me consider having a row of deep cycle bats in my bed if it's really true. However, I like my $15 a month electric bill. As little as I drive, probably wouldn't pay off anyhow.
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Last edited by johnmyster; 08-21-2008 at 11:17 AM..
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