Upgrading Alternator will Save Money? Now With Curve Charts!

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Mister Luck

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2016, 1500 , 5.7 V8
160 alt - to 220 alt

The settings in the (BCM) body control module for the (IBS) intelligent battery sensor are the same for the
(5.7 V8 2016, 2500) , as my 1500.

Do I need to upgrade anything else or is it a straight swap ?

Parts Supplier mentions upgraded Alts actually give you better gas mileage?

Rock Auto:
Tip: Alternators work best when operating between 30%-50% capacity. Upgrading to an alternator with higher Amp output than required may improve fuel economy and extend the life of your battery and replacement alternator. “
 
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Lyle Longboat

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Something I’d like to know and do as well. I have a alternator sitting on the shelf in my garage, may take back and opt for something with higher output.
 

kurek

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Oh man I remember going through the effort of calculating out fuel consumption for headlights years ago on ecomodder.com because somebody was going to disconnect a headlight to save fuel..

It was something like one gallon of gas saved per 40,000 miles of after-dark driving (because it only matters while the headlight would be on anyway).

Remember that your alternator is sized to deliver enough power for everything to work at the same time. Ignition firing at high rpm (16 plugs, that's 1.5-2A per 1000 rpm..) and fuel pump delivering ~395hp worth of fuel and headlights on and air conditioner clutch engaged and heated seats on and HVAC fan going full and stereo cranked to 11 and the ABS pump running traction control and a 5th wheel connected with incandescent running lights all along it and your electric power steering working and your inverter charging a laptop and your 12v port charging a phone and your 2nd 12v port charging a tablet...

If you're anywhere over ~50% of your alternator's full capacity during everyday driving I think it's pretty likely you're doing something pretty far out of the ordinary to begin with and rectifying that behavior might be more cost effective than trying to swap in a larger alternator that might take years or decades or centuries of hypothetical driving to realize a return on investment in fuel savings.
 

Jeepwalker

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Interesting idea. "May" is the operative term. Mfgrs would probably size accordingly if they could add to fuel economy. Pickup owners would save a lot on fuel if they didn't speed away from stop signs, and drove 5mph slower ...didn't use larger tires, and other fuel-wasting things people do (like me).

:cool:
 
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bm02tj

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I would say BS on better mileage as it take the same energy per watt produced
 

crash68

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Interesting idea. "May" is the operative term. Mfgrs would probably size accordingly if they could add to fuel economy.
for fuel economy purposes auto manufacturers can actually control the capacity of the alternator by varying the field voltage. The IBS feeds information to the ECM that controls the alternator.
 

Hemi395

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Went thru this a couple years ago. I was going to upgrade my 180 amp alternator to the 220 amp one thats on the HD 5.7 trucks. Got the 220 amp one home and realized the positive post and electrical connector on the 220 amp alt are facing up whereas the original 180 amp has them facing out the back of the alternator. The harness will reach, but not without unhooking and stretching the whole harness way more than I liked. Ended up returning the 220 amp alt.

You could always go with a custom alternator. PM me if you go this route, I can tell you what company NOT go with. Needless to say I'm back to the original 180 amp alt.

One thing to note, the fuse on the positive battery post is rated at 180 amp so if for whatever reason a higher amperage alternator puts out more than 180 amps its going to blow that fuse.

Honestly the cheapest and most beneficial thing you can do for your vehicles electrical system is to do the Big 3 upgrade.
 

GTyankee

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Chrysler products Alternators have a built in Voltage Regulator
The ECM controls the output
The ECM cuts off the Alternator about the time that the Battery reaches 85 to 90 something %

Many owners will run a Battery Tender to get a higher percentage of charge to the battery

Other owners don't care for the built in voltage regulator, They purchase a good quality Voltage Regulator & other components, then they mount it on the firewall, just like it was done in days gone by.
This comes in handy when you have a TT
 
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Mister Luck

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for fuel economy purposes auto manufacturers can actually control the capacity of the alternator by varying the field voltage. The IBS feeds information to the ECM that controls the alternator.
the 160amp alternator would still need to work harder than a 220 at lower RPM’s to keep up
 
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Mister Luck

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Went thru this a couple years ago. I was going to upgrade my 180 amp alternator to the 220 amp one thats on the HD 5.7 trucks. Got the 220 amp one home and realized the positive post and electrical connector on the 220 amp alt are facing up whereas the original 180 amp has them facing out the back of the alternator. The harness will reach, but not without unhooking and stretching the whole harness way more than I liked. Ended up returning the 220 amp alt.

You could always go with a custom alternator. PM me if you go this route, I can tell you what company NOT go with. Needless to say I'm back to the original 180 amp alt.

One thing to note, the fuse on the positive battery post is rated at 180 amp so if for whatever reason a higher amperage alternator puts out more than 180 amps its going to blow that fuse.

Honestly the cheapest and most beneficial thing you can do for your vehicles electrical system is to do the Big 3 upgrade.
Thanks I checked that
my 160 does have the rear post and the harness can be adjusted by replacing two zip tie straps on the left side front at the cylinder head and the block.
 

Wild one

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What’s the Big Three Upgrade ?
Upgraded wiring. Basically you upgrade or piggyback the alt feed to the fuse box,upgrade the wiring or piggyback another hot feed from the fuse box to the battery,then add a few extra grounds.There was a thread several years ago,over on the other Ram Forum,and guys were claiming they noticed a milege increase,i never noticed much in the way of a milege increase on my last 2 trucks,but i did notice the heater seemed to work better,and the headlights seemed a touch brighter.I ran several grounds from the battery to the engine/battery to frame.battery to fender grounds,and from the frame to the box.The one thing the ground from the frame to the box,back by the tailgate did cure was the issues i was having with the tailgate not unlocking or locking properly,the dealer put a new lock assembly in the truck when it was new,but it never cured the issue,after running a ground from the frame to the box,i never had another issue with the tailgate lock not working properly
 

Hemi395

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This is what I noticed as well. Headlights didn't dim quite as much (when I had halogens) when I turned the wheel and made the EPS draw current, when I turned the HVAC blower on high, etc.

Just seemed to make the electrical system more efficient overall.
 

crash68

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the 160amp alternator would still need to work harder than a 220 at lower RPM’s to keep up
In terms of percentage of output in relation to full rated load, a 110A load on the 160A alternator is 69% load but only a 50% load on the 220A alternator.
In respects to load on the engine effecting fuel economy, the load would be similar when the power output is the same.
Unless the OP has added a considerable amount of electrical load the the truck, there's not much benefit to up sizing the alternator. Most of the time it more beneficial to add a second battery.
 
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Mister Luck

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In terms of percentage of output in relation to full rated load, a 110A load on the 160A alternator is 69% load but only a 50% load on the 220A alternator.
In respects to load on the engine effecting fuel economy, the load would be similar when the power output is the same.
Unless the OP has added a considerable amount of electrical load the the truck, there's not much benefit to up sizing the alternator. Most of the time it more beneficial to add a second battery.
some Diesel rigs are designed with two alternators and two batteries those options in parts are available for our 4gen trucks

Some use voltaic arrays as alternatives for camper setups and extra batteries would benefit an expanded electrical system ideal for preppers

Magnetos are used in the most part by salt racers and dragsters where less weight is a premium

An alternator is basically a generator and a battery is a storage compartment for that energy, the alternator is only there to maintain the electrical storage not to re-charge the battery.

The need for additional electrical demand in modern vehicles is noted , added circuitry and at the same time seems the quality and diameter of the wiring keeps shrinking

I like the idea of “The Big Three Upgrade “ improved conductors and contact points, along with that, the option to use an upgraded alternator would contribute to the battery alternator relationship , and would save money in regards to parts and labor as maintenance.
 
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kurek

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I took the easy route with mine :Big Laugh: the base model RCSB Tradesman has the same alternator as a fully loaded Laramie quad cab.. but I don't have heated seats or heated mirrors or power seats or an overhead console or a subwoofer, probably a bunch of other stuff.

So boom oversized alternator!

Also by having a truck that's 2 feet shorter it weighs 20% less so I've got a 20% overbuilt suspension system and 20% better power to weight ratio.
 

mtofell

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Fuel economy is such a HUGE focus of auto manufacturers these days that you can bet every last possible trick has been done to try and bleed the absolute best MPGs possible. Back in 2014 when I got my 6.4 Hemi I remember reading they went with the 0 weight oil to cut down on resistance and save some fraction of a %. If a different alternator made that much of a difference Ram would have already done it. The days of tweaking things to make any real difference are over. Some really smart engineers have already done it.
 

BigTex13

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Does anyone make a grounding kit for our trucks that have thicker wires?
 

squadco343

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Went thru this a couple years ago. I was going to upgrade my 180 amp alternator to the 220 amp one thats on the HD 5.7 trucks. Got the 220 amp one home and realized the positive post and electrical connector on the 220 amp alt are facing up whereas the original 180 amp has them facing out the back of the alternator. The harness will reach, but not without unhooking and stretching the whole harness way more than I liked. Ended up returning the 220 amp alt.

You could always go with a custom alternator. PM me if you go this route, I can tell you what company NOT go with. Needless to say I'm back to the original 180 amp alt.

One thing to note, the fuse on the positive battery post is rated at 180 amp so if for whatever reason a higher amperage alternator puts out more than 180 amps its going to blow that fuse.

Honestly the cheapest and most beneficial thing you can do for your vehicles electrical system is to do the Big 3 upgrade.
We had this issue when I was working in the battery department at Sears years ago. If the terminals where in the wrong position we would undo the screws for the alternator housing and turn it to the correct position. Alternator ratings our base on 80 degree temperature ratings. When I was specing out emergency vehicles, I would always put in a higher amperage alternator do to amperage loss from heat. Hope this helps.
 
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squadco343

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Upgraded wiring. Basically you upgrade or piggyback the alt feed to the fuse box,upgrade the wiring or piggyback another hot feed from the fuse box to the battery,then add a few extra grounds.There was a thread several years ago,over on the other Ram Forum,and guys were claiming they noticed a milege increase,i never noticed much in the way of a milege increase on my last 2 trucks,but i did notice the heater seemed to work better,and the headlights seemed a touch brighter.I ran several grounds from the battery to the engine/battery to frame.battery to fender grounds,and from the frame to the box.The one thing the ground from the frame to the box,back by the tailgate did cure was the issues i was having with the tailgate not unlocking or locking properly,the dealer put a new lock assembly in the truck when it was new,but it never cured the issue,after running a ground from the frame to the box,i never had another issue with the tailgate lock not working properly
You are so right! Could have not said it any better.
 
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