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Old 02-14-2018, 08:25 PM   #35 (permalink)
sser2
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Quote:
Originally Posted by UFO View Post
You might be surprised how little draw the electrical load actually is, once the alternator has replaced the charge in the battery after a start. Do you really think it could be as much as 600W (12Vx50A)?
Night driving (no radio, no heater fan, fully charged battery) requires about 300 W electric power. With other losses (water pump, alternator inefficiency, alternator fan, bearings, serpentine belt) the drag on engine could be in the ballpark of 1 hp.

[/QUOTE]I am not disagreeing that you can get some fuel savings at night in a cold rainstorm, but then you have to plug in to recharge the battery, hopefully when you get to your destination.[/QUOTE]

At night, especially cold night, engine works inefficiently. If about 5-6 hp is needed for sustained 55 mph on level ground, 1 hp is 20% of that. Yes, the battery needs recharging after a long trip, but electric cars are much more aggravating in this regard.
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