Alternators, A just in case Scenario.

[poker4me007]

Something I've been wondering about...
K, I have the 95 amp alternator in my truck now , because of a head on accident I had back in 2000, I drive with my Head lights on all the time now, and most of my driving is during the day.
No day time running lights.
Now my question is if I needed a new alternator would it be better to replace it with a 130 amp , would I save any money on fuel? or would it be a wash?
In other words would you burn more gas with your Head lights on with a 130 amp or a 95 amp alternator?
I'm thinking it takes more effort to turn the 130 amp but then again if the 95 is maxing out ?
Battery is not an issue it stay's charged all the time.
Thanks...

 

[J_C]

It'd be close to a wash, the lower rotational mass of the smaller one might have a slight efficiency advantage but also a slight lifespan disadvantage running closer to max capacity. The efficiency difference might be less than that of different brands, major brands being more efficient than the cheap generics.

 

[1998Exp]

It'd be close to a wash, the lower rotational mass of the smaller one might have a slight efficiency advantage but also a slight lifespan disadvantage running closer to max capacity. The efficiency difference might be less than that of different brands, major brands being more efficient than the cheap generics.

Hmm, a pair of headlights (+tail lights) consumes about 150 Watts. Add the A/C clutch and blower, radio and what not, and you are perhaps at 300 Watts, while an alternator (even the smaller 95 Amp), will deliver close to 1000 Watts. Is the efficiency of the alternator even an issue for such a small load?

 

[J_C]

^ Won't be much different, but the question was asked.

However if something is running lower duty cycle with less winding impedance and a shorter duty cycle to suffer diode voltage drops, that would make it more efficient if all else were equal, but all else isn't equal when the 95A is a smaller physical size (and mass, and possibly pulley ratio too).