4.56 gears and fuel economy
#21
04-09-2006, 05:22 PM
RE: 4.56 gears and fuel economy
I know everybody's saying no change to your Limited Slip unit. But, I know on some axles once you get over 4.10's you have to install a different carrier than the 4.10 and lower gears use. If you had to change carrier, it seems likely you'd have to change Limited Slip units also. Could be that's not the case on this axle, I dunno - just a thought.
#22
04-09-2006, 05:58 PM
All Star
Join Date: Mar 2005
Location: Tracy, CA
Posts: 752
Likes: 0
Received 0 Likes
on
0 Posts
RE: 4.56 gears and fuel economy
i spent 8 hours in my truck yesterday (round trip to L.A. from s.f. bayarea)...and dam, i couldn't spend the time to check mileage...I was too busy layin into it because ther mustav been at least 4-5 rams that wanted to "run" from an 80mph start...dusted each an everone of them..the 4.56's totally increases the throttle response as i went from 80 - 115 very quickly....
#23
04-09-2006, 10:34 PM
RE: 4.56 gears and fuel economy
ORIGINAL: AIR RAM
Well there is a fine line... eventually raising your RPMs to a point will over come the benifit of decreasing the load... but we are talking a 300RPM (THREE HUNDRED RPMS) at 60MPH... thats NOTHING. As a matter in fact I had to remove my 20's and install a set of 17's that there 29.75" tall... so with the 29.75" tall tire and the 4.56's I got over 20.1 MPG on a2400 mile road trip from DFW to Deltona Floridy and back... this is to include ALL driving in traffic, around town/city and in between, not just highway. When I got home I averaged 456 miles a tank when all said and done...
Your not taking into consideration that you have a .67 overdrive. With this .67 overdrive your 3.55's become a 2.37 gear and your 3.92's become a 2.62 rear gear. Add the SUPER tall tires we have and that ratio gets even lower. On the FLIP side, the 4.56's become a 3.05 overall gear ratio... please tell me when a 3.05 gear became a BAD gear to have on the highway... Honestly its PERFECT for our combonation. And UNTILL you have experience with the 3rd Gen Ram and gears... your useing dated experience and your dated experience will cloud your judgement.
Again 30"+ tall tires, and a .67 overdrive are the reasons 4.56's are TAME on our 3rd Gen Rams. The stock ratios are literally to low and in overdrive they LUG the engine down... which consumes more fuel.
Also, on the third Gen Ram you do NOT need to recalabrate your SPEEDO after swaping gears... actualy there is NOTHING that needs to be done to the speedo after a gear swap. The speed sensor input is taking from your ring gear, so changing the ratio has ZERO effect on your MPH reading.
And no, Im not the only person who has swapped to 4.56's and GAINED MPG... your new around here and you have not been around long enough to follow the subject.
Im not speaking from opinion,again these are FACTS proven on the road in my 3rd Gen Ram!
ORIGINAL: stripper
If this is true, why not go 4.88's or even bigger? When will you stop gaining mileage? If what you are saying is true, that by raising rpm you are decreasing the load on the engine, then does that mean if you run 1000 rpm more your load would decrease even further, there by giving you even more MPG???
I only ask these questions trying to understand how you gained MPG. You are the only person that has increased gear by that much and gained MPG, at least that I have ever heard of. If you recalibrated your speedo and haven't changed tire sizes or anything likr that..........I don't see how more gear = better MPG.
Please help me understand.
Brad
ORIGINAL: AIR RAM
It depends on what your driving. If you own a 3Rd Gen Ram then 4.56's WILL improve your fuel economy up to 65-70MPH. you can thank the 32" tall tires and the .67/75 overdrive for that fact.
I went from 3.55's to 4.56's and gained 3MPG at 65MPH.... This is a FACT and not an opinion.
DONT FEAR THE GEAR!!
And RPM’s alone do NOT dictate fuel consumption. Actually RPM’s have a smaller role in actual fuel economy than most think. It the load on the engine at ANY given RPM that determines your fuel economy... The 4.56's will only raise your RPM’s approximately 300RPMs @60MPH. The 300RPMs will lower the load on the engine and move the mechanical advantage to the rear end... With this less load on the engine you will see better fuel economy.
Actually you will see GREAT fuel economy from 0MPH all the way to 65-70MPH... I can get 20+MPG at 65MPH with my 4.56's. At 75-80MPH I can get approximately 16-17MPG so even at 80MPH its not so bad... and I have had it well past the 120MPH mark on the Speedo... all the way to "L1"... so top end is there as well.
SPEED SAFE, AIR RAM
It depends on what your driving. If you own a 3Rd Gen Ram then 4.56's WILL improve your fuel economy up to 65-70MPH. you can thank the 32" tall tires and the .67/75 overdrive for that fact.
I went from 3.55's to 4.56's and gained 3MPG at 65MPH.... This is a FACT and not an opinion.
DONT FEAR THE GEAR!!
And RPM’s alone do NOT dictate fuel consumption. Actually RPM’s have a smaller role in actual fuel economy than most think. It the load on the engine at ANY given RPM that determines your fuel economy... The 4.56's will only raise your RPM’s approximately 300RPMs @60MPH. The 300RPMs will lower the load on the engine and move the mechanical advantage to the rear end... With this less load on the engine you will see better fuel economy.
Actually you will see GREAT fuel economy from 0MPH all the way to 65-70MPH... I can get 20+MPG at 65MPH with my 4.56's. At 75-80MPH I can get approximately 16-17MPG so even at 80MPH its not so bad... and I have had it well past the 120MPH mark on the Speedo... all the way to "L1"... so top end is there as well.
SPEED SAFE, AIR RAM
If this is true, why not go 4.88's or even bigger? When will you stop gaining mileage? If what you are saying is true, that by raising rpm you are decreasing the load on the engine, then does that mean if you run 1000 rpm more your load would decrease even further, there by giving you even more MPG???
I only ask these questions trying to understand how you gained MPG. You are the only person that has increased gear by that much and gained MPG, at least that I have ever heard of. If you recalibrated your speedo and haven't changed tire sizes or anything likr that..........I don't see how more gear = better MPG.
Please help me understand.
Brad
Your not taking into consideration that you have a .67 overdrive. With this .67 overdrive your 3.55's become a 2.37 gear and your 3.92's become a 2.62 rear gear. Add the SUPER tall tires we have and that ratio gets even lower. On the FLIP side, the 4.56's become a 3.05 overall gear ratio... please tell me when a 3.05 gear became a BAD gear to have on the highway... Honestly its PERFECT for our combonation. And UNTILL you have experience with the 3rd Gen Ram and gears... your useing dated experience and your dated experience will cloud your judgement.
Again 30"+ tall tires, and a .67 overdrive are the reasons 4.56's are TAME on our 3rd Gen Rams. The stock ratios are literally to low and in overdrive they LUG the engine down... which consumes more fuel.
Also, on the third Gen Ram you do NOT need to recalabrate your SPEEDO after swaping gears... actualy there is NOTHING that needs to be done to the speedo after a gear swap. The speed sensor input is taking from your ring gear, so changing the ratio has ZERO effect on your MPH reading.
And no, Im not the only person who has swapped to 4.56's and GAINED MPG... your new around here and you have not been around long enough to follow the subject.
Im not speaking from opinion,again these are FACTS proven on the road in my 3rd Gen Ram!
It is now clear to me...............you have the best MPG Hemi Ram out there! 20.1 mpg is great. I personally think that you should sell a complete package that you can gaurantee would get the gas mileage to all of the people on this board. In these times of high gas prices you would most likely sell a lot. As most people are not seeing this kind of mileage.
As for not being around here long............you are right, but I have been around cars and trucks for over twnety five years. I have done a ton of gear swaps on multiple cars and trucks and I have yet to see anyone of them gain MPG.
9 times out of 10, except in your "proven" case, more gear equals less MPG. Ask yourself this, if a 4.56 picks up MPG....why didn't Dodge use this gear from the factory?? I am pretty sure that a more fuel friendly truck would sell even better and would help Dodge with EPA and gas guzzler taxes??
If you take away taking about the gas mileage with 4.56's you will be left with only things that we all want..............quicker acceleration, and a more responsive truck. No real draw backs except the great debate on the MPG. Now if AIRRAM can get a duplicate package of what he did to his truck, including the gear............we can have our cake and eat it too!! Fuel mileage and the biger gear.
Brad
#24
04-09-2006, 10:36 PM
RE: 4.56 gears and fuel economy
ORIGINAL: chefred112
i spent 8 hours in my truck yesterday (round trip to L.A. from s.f. bayarea)...and dam, i couldn't spend the time to check mileage...I was too busy layin into it because ther mustav been at least 4-5 rams that wanted to "run" from an 80mph start...dusted each an everone of them..the 4.56's totally increases the throttle response as i went from 80 - 115 very quickly....
i spent 8 hours in my truck yesterday (round trip to L.A. from s.f. bayarea)...and dam, i couldn't spend the time to check mileage...I was too busy layin into it because ther mustav been at least 4-5 rams that wanted to "run" from an 80mph start...dusted each an everone of them..the 4.56's totally increases the throttle response as i went from 80 - 115 very quickly....
Now thats what the 4.56's we do for you!! Good freeway kills!
Brad
#25
04-09-2006, 10:38 PM
#26
04-09-2006, 11:05 PM
Captain
Join Date: Dec 2004
Location: New Castle Delaware
Posts: 679
Likes: 0
Received 0 Likes
on
0 Posts
#27
04-10-2006, 12:04 AM
Join Date: Mar 2006
Location:
Posts: 417
Likes: 0
Received 0 Likes
on
0 Posts
RE: 4.56 gears and fuel economy
not the right thing to say in the Dodge Forum dude, an econo-rocket is still an econo-rocket no matter how much u dress it up. Also, this is about 4.56 gears and not truck replacements so you need to dump the nasty econocrap and go back to the Hemi. Just deal with the bad gas mileage.
#28
04-10-2006, 12:23 AM
RE: 4.56 gears and fuel economy
been checking out the hot gear topic. i had 4.56 put in my o5 2500hd. they were the
factory aam gears. i run 37's and can pull 2wd silverados with my hemi. 4.88s are
not available i checked with everybody for months. 4.56s adn 35's are perfect. now
im waiting for a front locker to become available. if anybody has info let me know.
oh and the dynatrac free spin hub kit is in the mail!
factory aam gears. i run 37's and can pull 2wd silverados with my hemi. 4.88s are
not available i checked with everybody for months. 4.56s adn 35's are perfect. now
im waiting for a front locker to become available. if anybody has info let me know.
oh and the dynatrac free spin hub kit is in the mail!
#29
04-10-2006, 09:13 AM
RE: 4.56 gears and fuel economy
When considering gear options - look beyond the usual and consider resale as well as first cost.
The Quick Change style of differential has been around for more than 30 years, and allows changing the ratio in less than 30 minutes. Since the reliability of the 9.25 differential seems to have continuing problems replacing the entire axle may save a rebuild down the road. Notice this diff is available in either iron or aluminum. An axle change is also an opportunity to swap out the heavy leaf springs to lighter monoleaf, composite or air systems.
http://www.hotrodscustomstuff.com/PS-Winters.html
There is the option of putting in a NV5600 six speed. The cost is higher but in resale value a NV5600/5.7Hemi would be unique. As the NV5600 is highly regarded due to its use behind Cummins Ram diesels, there might even be premium in resale. Many people would like a reliable manual trans Hemi 1500 pickup.
http://www.drivetrain.com/nv5600.html
There is the GearVendors underdrive/overdrive unit. Again the cost is higher but GearVendor units command high used prices on eBay, Craigslist, or Mopar 'For Sale' forums. (these units can be found under some medium duty Ford trucks in salvage yards)
http://www.gearvendors.com/
The Klune-V Underdrive is perhaps too much of a ratio change for the dragstrip but is better for 'real truck' off road work
http://www.klunev.com/
It is also possible to have custom sun, ring and planetary pistons cut for the 45/545 auto trans guts.
So far no one is advertising this - so if you enjoy machine shop work and are looking for a small business to run there is an opportunity.
Think outside the box.
The Quick Change style of differential has been around for more than 30 years, and allows changing the ratio in less than 30 minutes. Since the reliability of the 9.25 differential seems to have continuing problems replacing the entire axle may save a rebuild down the road. Notice this diff is available in either iron or aluminum. An axle change is also an opportunity to swap out the heavy leaf springs to lighter monoleaf, composite or air systems.
http://www.hotrodscustomstuff.com/PS-Winters.html
There is the option of putting in a NV5600 six speed. The cost is higher but in resale value a NV5600/5.7Hemi would be unique. As the NV5600 is highly regarded due to its use behind Cummins Ram diesels, there might even be premium in resale. Many people would like a reliable manual trans Hemi 1500 pickup.
http://www.drivetrain.com/nv5600.html
There is the GearVendors underdrive/overdrive unit. Again the cost is higher but GearVendor units command high used prices on eBay, Craigslist, or Mopar 'For Sale' forums. (these units can be found under some medium duty Ford trucks in salvage yards)
http://www.gearvendors.com/
The Klune-V Underdrive is perhaps too much of a ratio change for the dragstrip but is better for 'real truck' off road work
http://www.klunev.com/
It is also possible to have custom sun, ring and planetary pistons cut for the 45/545 auto trans guts.
So far no one is advertising this - so if you enjoy machine shop work and are looking for a small business to run there is an opportunity.
Think outside the box.
#30
04-11-2006, 12:17 AM
RE: 4.56 gears and fuel economy
ORIGINAL: stripper
It is now clear to me...............you have the best MPG Hemi Ram out there! 20.1 mpg is great. I personally think that you should sell a complete package that you can gaurantee would get the gas mileage to all of the people on this board. In these times of high gas prices you would most likely sell a lot. As most people are not seeing this kind of mileage.
As for not being around here long............you are right, but I have been around cars and trucks for over twnety five years. I have done a ton of gear swaps on multiple cars and trucks and I have yet to see anyone of them gain MPG.
9 times out of 10, except in your "proven" case, more gear equals less MPG. Ask yourself this, if a 4.56 picks up MPG....why didn't Dodge use this gear from the factory?? I am pretty sure that a more fuel friendly truck would sell even better and would help Dodge with EPA and gas guzzler taxes??
If you take away taking about the gas mileage with 4.56's you will be left with only things that we all want..............quicker acceleration, and a more responsive truck. No real draw backs except the great debate on the MPG. Now if AIRRAM can get a duplicate package of what he did to his truck, including the gear............we can have our cake and eat it too!! Fuel mileage and the biger gear.
Brad
It is now clear to me...............you have the best MPG Hemi Ram out there! 20.1 mpg is great. I personally think that you should sell a complete package that you can gaurantee would get the gas mileage to all of the people on this board. In these times of high gas prices you would most likely sell a lot. As most people are not seeing this kind of mileage.
As for not being around here long............you are right, but I have been around cars and trucks for over twnety five years. I have done a ton of gear swaps on multiple cars and trucks and I have yet to see anyone of them gain MPG.
9 times out of 10, except in your "proven" case, more gear equals less MPG. Ask yourself this, if a 4.56 picks up MPG....why didn't Dodge use this gear from the factory?? I am pretty sure that a more fuel friendly truck would sell even better and would help Dodge with EPA and gas guzzler taxes??
If you take away taking about the gas mileage with 4.56's you will be left with only things that we all want..............quicker acceleration, and a more responsive truck. No real draw backs except the great debate on the MPG. Now if AIRRAM can get a duplicate package of what he did to his truck, including the gear............we can have our cake and eat it too!! Fuel mileage and the biger gear.
Brad
Now I’m not sure if I get the BEST fuel economy out of EVERY RAM on the road... but I do know that I have chosen my mods carefully... so its quite possible that due to my experience with the 3rd Gen Ram... I may know what I’m talking about. Personally I would rather take advice from someone with DIRECT hands on experience than someone with indirect experience with another vehicle. I think its great you have chosen to offer advice... but to jump on me like I’m saying something wrong and the fact that you have ZERO experience with the 3rd Gen Ram (As well as HANKL) I would think that my experience out weighs yours in this case... You have spent allot of money for my results... you have spent NONE but have an abundance of advice...???
So its good that you have done a few gear swaps... but this does not give you experience with the 3rd Gen Ram.. your just here to peddle your parts this is no secret. Your advice is just as good as any advice coming from HANKL... neither of you two have done anything with gears in a 3rd Gen Ram regardless of how much you THINK you know... So before you jump on me telling me Im wrong... go spend some money on your 3rd Gen Ram if you even have one... we all know HANKL does not have one!
ORIGINAL: dodgetk81
I have a Powerwagon with 4.56 And the factory 33" tires. Its a 5speed auto and Im getting 11.0 MPG city/highway.
I have a Powerwagon with 4.56 And the factory 33" tires. Its a 5speed auto and Im getting 11.0 MPG city/highway.
I have NOTHING to gain by sharing my EXPERIENCE... NOTHING. Why would I share this experience other than to help others improve there all round performance. If your unsure... my first advice is to ignore HANKL... he will just miss lead you with his limited experience on his 1st Gen Ram... Then do a search and look up other members who have done the swap... I’m not the only one. Ask them what there results are... Don’t just listen to me... but DO listen to those with the actual hands on experience with the 3rd Gen Ram.
SPEED SAFE, AIR RAM