Alternator deletes have been shown to increase fuel economy as much as 10%. However, extra deep-cycle batteries (and/or another form of power) must be used as a replacement, and their cost may offset any economic savings of reduced fuel consumption.
That said, if your regular starting battery is in need of replacement anyway, it could be replaced with a good deep-cycle battery for not too much more money.
Instructions for mod
Remove your alternator belt.
Note: you will need some other method of charging your battery for your car to work properly. Such as solar panels and/or externally powered battery charger.
Please enter your user name and any relevant data in the table
|User Name||Car Make, Model, Year||Cost of Mod||Time to Perform Mod||MPG Before Mod||MPG After Mod||MPG improvement||Instruction Link|
|MetroMPG||Pontiac, Firefly, 1998||$0||70.68||78.08||7.4 (10.4%)||Test: Alternator vs. no alternator = 10% MPG gain @ 70 km/h|
|TOOSTUBBORN2FAIL||Neon||$0||42.7||43.6||2.1%||Alternatorless Test in a Neon (still disappointing, but now w/slightly better results|
Problems / Consequences of mod
- Damage to starting battery if discharged below 20%
- Deep cycle batteries can take 50% discharge
- Lithium batteries can take an 80% discharge
- Car may stall out while driving without energy to fire injectors, spark and run fuel pump
- Some ecomodders have found poor car performance when the alternator is disconnected due to the lower voltage of the battery when the alternator is running
http://ecomodder.com/wiki/index.php/Bigger_battery (<<<must have prereq)