MPG and gear change question - Ranger-Forums - The Ultimate Ford Ranger Resource


Drivetrain Tech General discussion of drivetrain for the Ford Ranger.

Reply
 
LinkBack Thread Tools Search this Thread
  #1  
Old 03-01-2009
robert99ranger's Avatar
RF Veteran
Thread Starter
iTrader: (4)
 
Join Date: Aug 2007
Location: Indiana/Mississippi
Posts: 5,807
MPG and gear change question

Question, whats gonna happen to my mileage when I change my gears to 4.10 from 3.73. Right now, I am only getting like 20 mpg on the highway and the truck really feels like it is boggin. I think I am having to use more gas to keep it going lets say at 70 than I did. So, will my mpg go up when I change to 4.10 or go even more down?
Reply With Quote
  #2  
Old 03-01-2009
chainfire's Avatar
Member
iTrader: (1)
 
Join Date: Oct 2007
Location: Mission B.C.
Posts: 3,126
before you swap, when was the last time you have done a tune up? There are sooo many factors to milage that it is hard to say if it will increase a substantial amount. Are you buying gears? or swaping in a rear end that already has them?
Reply With Quote
  #3  
Old 03-01-2009
offroadn_redneck's Avatar
Member
 
Join Date: Feb 2009
Location: San Antonio, TX
Posts: 776
You say its bogging? First try and run some BK44G through that puppy. That normally gets my cars up and kickin.
Reply With Quote
  #4  
Old 03-01-2009
robert99ranger's Avatar
RF Veteran
Thread Starter
iTrader: (4)
 
Join Date: Aug 2007
Location: Indiana/Mississippi
Posts: 5,807
Swap in a rear end that already has it. I'm talking to a guy about it.

If I am in a good head wind, it is 4th gear most of the way.

Over winter break, I tuned the truck up. All new plugs, timing belt, timing belt tensioner, water pump, air filter, changed oil, new radiator fluid, cant think of what else.

I was just wondering in general if the mileage should go up or down more.
Reply With Quote
  #5  
Old 03-02-2009
Fx4wannabe01's Avatar
RF Veteran
iTrader: (23)
 
Join Date: May 2005
Location: Boring, Oregon
Posts: 21,721
'only' 20. lmao.
Reply With Quote
  #6  
Old 03-02-2009
God,Country,FORD's Avatar
Member
iTrader: (1)
 
Join Date: Nov 2007
Location: Red Oak, IA
Posts: 2,468
dude, you should feel lucky to get 20mpg.. Im not sure what im getting in my truck right now as i just got it back, but i know its no where near 20.. my jeep.. HA.. try 170 miles per TANK... you do the math
Reply With Quote
  #7  
Old 03-02-2009
robert99ranger's Avatar
RF Veteran
Thread Starter
iTrader: (4)
 
Join Date: Aug 2007
Location: Indiana/Mississippi
Posts: 5,807
I mean, I understand that bigger tires = less mpg but I was just wanting to know if it is going to increase any with the gear change. I was getting 24 highway now 19.
Reply With Quote
  #8  
Old 03-02-2009
God,Country,FORD's Avatar
Member
iTrader: (1)
 
Join Date: Nov 2007
Location: Red Oak, IA
Posts: 2,468
from what i understand about gears and larger tires, once you get bigger tires, if you stay with the high gears, ie, 3.73's, your truck is going to have to work harder.. less mpg.. Lower gears, ie 4.10, 4.56, less work, higher mpg..

i could be wrong though..
Reply With Quote
  #9  
Old 03-02-2009
Downey's Avatar
RF Veteran
iTrader: (1)
 
Join Date: Oct 2007
Location: Muncy, PA
Posts: 8,470
you will probably see some of an increase but probably not back to 24 mpg
Reply With Quote
  #10  
Old 03-02-2009
ColdNapalm's Avatar
Member
 
Join Date: Sep 2008
Location: Jacksonville, Florida
Posts: 499
Ya you would see an increase but lose top speed i think?
Reply With Quote
  #11  
Old 03-02-2009
MemphisSenior's Avatar
Member
 
Join Date: Mar 2007
Location: Spring City, TN
Posts: 331
Are you sure you're calculating it correctly? With 31" tires (stock is about 27.5") your speedometer,
odometer are going to read about 13% slow. That is when the odometer says you have traveled 100 miles.
You have actually traveled 113. Using that as a basis, if your odometer says you have traveled 100 miles
and you use 5 gals, that would indicate your getting 20 MPG.
However if you have actually traveled 113 and use 5 gals, your mileage would be about 23. Pretty close.
Easiest way to find out, is to check your odometer against the mile markers on the hwys. Pref an interstate.

Last edited by MemphisSenior; 03-02-2009 at 12:42 AM.
Reply With Quote
  #12  
Old 03-02-2009
MemphisSenior's Avatar
Member
 
Join Date: Mar 2007
Location: Spring City, TN
Posts: 331
Quote:
Originally Posted by ColdNapalm View Post
Ya you would see an increase but lose top speed i think?

Top speed would be about the same. Lower gearing would be offset by the
larger diameter of the tires. If the tire size remained stock, then you would lose
top speed because you would reach max RPM at a slower speed.
Reply With Quote
  #13  
Old 03-02-2009
robert99ranger's Avatar
RF Veteran
Thread Starter
iTrader: (4)
 
Join Date: Aug 2007
Location: Indiana/Mississippi
Posts: 5,807
I am using a scan gauge to see what I am getting. And I did already change the scan gauge to 13% when I got it at xmas.

So, looks like spring break I need to go to the junkyard and find me a rear end. Hopefully this time I will find one unlike the last 20.
Reply With Quote
  #14  
Old 03-02-2009
wydopnthrtl's Avatar
Member
iTrader: (2)
 
Join Date: Dec 2005
Location: SE, Mi
Posts: 2,342
I've spent a lot of time in the last 6 months studying MPG at 70mph. (I have a FX4 w/4.10s)

What you need to look at more than anything is "load". Reducing load will gain you the most mpg.

Things like headwind, height off the ground, dragging brakes, being behind another car/truck, ambient temps, rpms, & timing (vs the octane used) all play a part in "load".

As load goes up.. timing goes down & fuel gets added.

Just going from 3.73s to 4.10s alone will do two things at 70mph. Load will go down.. and rpms will go up. So your gaining in one area and loosing in another.


IMO.. adjusting the timing VIA a tune would give you more feeling of power than the gear swap would.
Reply With Quote
  #15  
Old 04-06-2009
Ranger24's Avatar
Member
 
Join Date: Jul 2008
Location: Fowlerville, MI
Posts: 10
I have 4.10 gears and im only getting 15 mpg city and 19 highway, i think you would get better gas millage if you stayed with the 3.73 gears
Reply With Quote
  #16  
Old 04-06-2009
brianjwilson's Avatar
Member
 
Join Date: Nov 2006
Location: Hillsboro, Oregon
Posts: 3,650
I think you'll pick up some mileage swapping to 4.10 gears. It won't be as good as stock, but it will help.
Hell a lot of the 4 cyl rangers come with 4.10's from the factory with 225's or whatever, you could probably afford to swap to 4.30's with 31's.
My Jetta (6 speed vr6) runs high rpm's on the highway (around 3000rpm at 70mph), but gets 28-30mpg at that speed. Sure, the rpm's are high, but it requires little throttle (little load).
Reply With Quote
  #17  
Old 04-06-2009
robert99ranger's Avatar
RF Veteran
Thread Starter
iTrader: (4)
 
Join Date: Aug 2007
Location: Indiana/Mississippi
Posts: 5,807
I still have not found what I want at the junkyard. Hopefully something will come up soon.
Reply With Quote
  #18  
Old 04-06-2009
nross's Avatar
Member
 
Join Date: Nov 2008
Location: Binghamton, NY
Posts: 256
I have a 05 ranger with the 4:10 gears. They came with the truck from day one. I get terrible mileage usually... sometime if I drive really really nice I get 17 combined. The truck does feel like it has more power with them. But if I was not going to get teh truck brand new for 16k (whicha t the time it was a really good deal).... I would have ordered the truck with teh 3.73, I believe the fuel economy would have been better.

Also I noticed with the 4:10 my truck wants to roast the tires if its any bit wet out... but im not gear head... just seems like it to me compared to the old f150 1992 I had with the 373 and a standard... I have an auto now.
Reply With Quote
  #19  
Old 04-06-2009
Riceman's Avatar
Member
 
Join Date: Dec 2008
Location: GA
Posts: 576
Quote:
Originally Posted by nross View Post
I have a 05 ranger with the 4:10 gears. They came with the truck from day one. I get terrible mileage usually... sometime if I drive really really nice I get 17 combined. The truck does feel like it has more power with them. But if I was not going to get teh truck brand new for 16k (whicha t the time it was a really good deal).... I would have ordered the truck with teh 3.73, I believe the fuel economy would have been better.

Also I noticed with the 4:10 my truck wants to roast the tires if its any bit wet out... but im not gear head... just seems like it to me compared to the old f150 1992 I had with the 373 and a standard... I have an auto now.
You have a 4.0, he has the 2.5 huge difference. I think the 4.10 would help, would compensate for the taller tires and bring you back closer to stock.
Reply With Quote
  #20  
Old 04-06-2009
brianjwilson's Avatar
Member
 
Join Date: Nov 2006
Location: Hillsboro, Oregon
Posts: 3,650
Quote:
Originally Posted by nross View Post
I have a 05 ranger with the 4:10 gears. They came with the truck from day one. I get terrible mileage usually... sometime if I drive really really nice I get 17 combined. The truck does feel like it has more power with them. But if I was not going to get teh truck brand new for 16k (whicha t the time it was a really good deal).... I would have ordered the truck with teh 3.73, I believe the fuel economy would have been better.

Also I noticed with the 4:10 my truck wants to roast the tires if its any bit wet out... but im not gear head... just seems like it to me compared to the old f150 1992 I had with the 373 and a standard... I have an auto now.
Apples to oranges comparison. Different engine, transmission.

Even the new 4.0L engines can be slugs with 4x4 and 3.73 gears, especially if you're towing or hauling (it is a truck after all).
The SOHC 4.0L doesn't have as much low end as the older OHV 4.0L, but it revs much higher and smoother, and makes more top end power, which is why the 4.10's work well with it.
I got 18 mpg on the highway a few times with the sport trac in stock condition with 4.10's and 255/70/16's.
Reply With Quote
  #21  
Old 04-23-2009
blueranger06's Avatar
Member
iTrader: (1)
 
Join Date: Mar 2009
Location: Lake Worth, FL
Posts: 246
I got 18 mpg at 80 mph and my yzf 450 in the bed. Your truck is struggling with your tire size so you need to upgrade to 4.10 and your mpg will come back. Not fully but close.
Reply With Quote
  #22  
Old 04-23-2009
robert99ranger's Avatar
RF Veteran
Thread Starter
iTrader: (4)
 
Join Date: Aug 2007
Location: Indiana/Mississippi
Posts: 5,807
Quote:
Originally Posted by blueranger06 View Post
I got 18 mpg at 80 mph and my yzf 450 in the bed. Your truck is struggling with your tire size so you need to upgrade to 4.10 and your mpg will come back. Not fully but close.
Ya, I know it wont be fully but the mileage will hopefully be a little better and get me back to stock power band.

I just need to find what I am looking for in the junkyard still. I go every chance I get.
Reply With Quote
  #23  
Old 04-23-2009
Melt's Avatar
Member
iTrader: (1)
 
Join Date: Apr 2008
Location: Denver, CO
Posts: 3,392
yea this is why i wasnt even willing to up to 29" tires ... actually went down a size im ridin 215/70/15's lol
Reply With Quote
  #24  
Old 04-24-2009
blueranger06's Avatar
Member
iTrader: (1)
 
Join Date: Mar 2009
Location: Lake Worth, FL
Posts: 246
good luck!
Reply With Quote
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Front and Reat Diff gear oil change for 04 Ranger 4x4? fazzer Drivetrain Tech 11 07-22-2011 11:24 PM
mpg<>gear question... hozII General Ford Ranger Discussion 16 03-03-2011 06:29 PM
Actual Speed Change from New Tire Size and Gear Change Calculator KLC General Technical & Electrical 13 12-02-2009 01:53 AM
98 3.0 MPG Log (shows how mods affected MPG) Marcaronio 2.9L & 3.0L V6 Tech 23 05-11-2007 09:11 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -6. The time now is 08:51 PM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.