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Old 12-01-2019, 01:33 PM   #9 (permalink)
2000mc
herp derp Apprentice
 
Join Date: Oct 2008
Location: Lawrence, KS
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Saturn-sold - '99 saturn sc1
Team Saturn
90 day: 28.28 mpg (US)

Yukon - '03 GMC Yukon Denali
90 day: 13.74 mpg (US)
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Quote:
Originally Posted by redpoint5 View Post
That doesn't make sense. The highest efficiency gains to be had with PWM would be at the lowest settings and have diminishing returns the higher the "speed" (lower resistance) up until the "hi" setting, which is a straight connection to the battery.
It sounds counter intuitive on the surface, but a greater percentage of a smaller number wouldn’t necessarily be more than a smaller percentage of a greater number or vice versa. Jrmichler's blower doubled its draw from speed 1 to 2, so if the efficiency gains aren't double on low vs setting 2, you would be saving more power on setting 2 than 1.
I imagine this could also vary from vehicle to vehicle. I’m also regurgitating info i saw years ago I can’t see from some chart on Pulse-Width Modulated Fan Controllers for Automotive Applications | PowerGuru - Power Electronics Information Portal
But maybe you can with a different browser. But as I recall, it seemed like the squeeze wasn’t going to be worth the juice at the lowest setting
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