Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - Test: Alternator vs. no alternator = 10% MPG gain @ 70 km/h

Nerys · 06-05-2012, 01:48 AM

First some of us are using metro's this means no power steering or anything else at all actually except the water pump. also our cars are much lower "power" than most cars. so a single deep cycle auto battery will be MORE than enough power for the average commute if you charge it up each night and don't go below 50% DOD.

Second people who turn them on and off are not draining the battery to such a degree that the alternator is going to "work" all that hard.

Third. on many of our car's alternators are dirt cheap and last a long time. even if we cut the life span of the alternator in HALF the savings of fuel will more than compensate for this MANY times over. 10% for me is $330 a year. MORE THAN DOUBLE what even a brand new alternator and battery cost if I had to replace them YEARLY.

same with the batteries. I get good batteries for $20. 10% fuel savings will save me $20 in a couple weeks. so even if I have to buy another battery every YEAR I am saving a TON of cash way more than the cost of replacing both the alternator AND battery on a yearly basis. IE worth it.

MY plan is to replace the pulley water pump with an electric water pump.

once I do that then I no longer need a belt AT ALL except to turn the alternator. so I remove the belt and use 2 deep cycle (I have a long commute) and will charge at work and charge at home as needed.

I also plan to toss a solar panel on the roof. in the summer I might not need to plug in at all to charge up.

just got to save up the cash for the electric water pump.

06-05-2012, 01:48 AM	#215 (permalink)
Nerys Grrr :-) Join Date: May 2008 Location: Levittown PA Posts: 800 Cherokee - '88 Jeep Cherokee 90 day: 19.44 mpg (US) Ryo-Ohki - '94 Geo Metro Xfi 90 day: 50.15 mpg (US) Vger 2 - '00 Plymouth Grand Voyager SE Ninja - '89 Geo Tracker 90 day: 30.27 mpg (US) Thanks: 12 Thanked 31 Times in 25 Posts	First some of us are using metro's this means no power steering or anything else at all actually except the water pump. also our cars are much lower "power" than most cars. so a single deep cycle auto battery will be MORE than enough power for the average commute if you charge it up each night and don't go below 50% DOD. Second people who turn them on and off are not draining the battery to such a degree that the alternator is going to "work" all that hard. Third. on many of our car's alternators are dirt cheap and last a long time. even if we cut the life span of the alternator in HALF the savings of fuel will more than compensate for this MANY times over. 10% for me is $330 a year. MORE THAN DOUBLE what even a brand new alternator and battery cost if I had to replace them YEARLY. same with the batteries. I get good batteries for $20. 10% fuel savings will save me $20 in a couple weeks. so even if I have to buy another battery every YEAR I am saving a TON of cash way more than the cost of replacing both the alternator AND battery on a yearly basis. IE worth it. MY plan is to replace the pulley water pump with an electric water pump. once I do that then I no longer need a belt AT ALL except to turn the alternator. so I remove the belt and use 2 deep cycle (I have a long commute) and will charge at work and charge at home as needed. I also plan to toss a solar panel on the roof. in the summer I might not need to plug in at all to charge up. just got to save up the cash for the electric water pump.