what's the MPG loss for 355 to 410 gears. - F150online Forums



what's the MPG loss for 355 to 410 gears.

Reply
 
 
  #1  
Old 08-04-2009, 11:46 AM
Senior Member
Thread Starter
 
Join Date: Jul 2009
Location: Chicago, IL
Posts: 603
what's the MPG loss for 355 to 410 gears.

ok i don't want to hear any B.S. about the faster acceleration making up for the lost MPGs. i just want to know about how much MPGs i may lose if i switch it. thank you.
Reply With Quote
  #2  
Old 08-04-2009, 11:57 AM
Senior Member
 
Join Date: Oct 2008
Location: Fort Myers, FL
Posts: 1,742
It depends on your driving style, city vs highway driving, and tire size. If you have slightly larger tires and live and drive in the city it might go up.

Lots of different factors.
Reply With Quote
  #3  
Old 08-04-2009, 12:02 PM
illness95's Avatar
Senior Member
 
Join Date: Jan 2006
Location: Clinton Twp. MI
Posts: 873
im about to do the same swap.. my truck already sucks at a best of 15 mpg how much worse could it get..
Reply With Quote
  #4  
Old 08-04-2009, 12:04 PM
Senior Member
Thread Starter
 
Join Date: Jul 2009
Location: Chicago, IL
Posts: 603
just an average driving style, during the week, also i mainly just wanted to know what other people lost, when they switched, if i had to guess i would think maybe 1-2MPGs, maybe 3 cause i'd rather over estimate then be under.
Reply With Quote
  #5  
Old 08-04-2009, 04:25 PM
glc
glc is offline
Senior Member
 
Join Date: Dec 2006
Location: Joplin MO
Posts: 33,570
If you keep your foot out of the firewall, you probably won't lose any mileage. Make sure you adjust the speedo/odo for the different gears.
Reply With Quote
  #6  
Old 08-04-2009, 06:36 PM
Senior Member
 
Join Date: Dec 1999
Location: California
Posts: 1,249
The rpm change for any gear mod is 300 rpm for each .25 gear ratio change- in summary you are only looking at about 300 more rpm.
Reply With Quote
  #7  
Old 08-04-2009, 08:19 PM
Senior Member
 
Join Date: Aug 2006
Location: Summerville, SC
Posts: 1,224
it mostly depends on whether you drive city or highway. if you drive mostly city then there's a good chance you'll see an increase.

highway it may drop 1 or 2 mpg.
Reply With Quote
  #8  
Old 08-05-2009, 03:44 PM
Senior Member
Thread Starter
 
Join Date: Jul 2009
Location: Chicago, IL
Posts: 603
well i work at UPS and start at 3 in the morning, it's all city driving , but at 3:00AM so, kind of an average and i figured that city MPGs would go up, also i probably should have mentioned this sooner but this stock wheels and suspension, so this is for more of a street/strip application. and i have also been thinking maybe, 373s but 410s are $20 cheaper. thanks for all of your help so far.
Reply With Quote
  #9  
Old 08-05-2009, 04:11 PM
Senior Member
 
Join Date: Nov 2002
Location: Waco/Houston
Posts: 3,102
I gained mpg around town, stayed the same on the highway.
Reply With Quote
  #10  
Old 08-10-2009, 12:58 PM
Senior Member
 
Join Date: Jun 2002
Posts: 4,243
What he said^^^. I'm assuming you guys that suspect a loss have never actually done it?? I GAINED 1-2 everywhere, and have seen a best of 3 mpg increase. There are ZERO downsides from doing a gear change.

3.55 to 3.73 is NOT worth the cost or the effort for such a small change in ratio. You will not regret 4.10's. It completely transformed my truck across the board.

Last edited by Galaxy; 08-10-2009 at 01:02 PM.
Reply With Quote
  #11  
Old 08-13-2009, 07:52 AM
Member
 
Join Date: Mar 2009
Posts: 57
3.73 to 4.10...worth it?

Hi

I bought a used 2005 fx4 (50K miles) with 6 inch lift and it has 325/60/18 tires. I also added Custom 87 tunes (performance, tow, MPG) from VMP but am just not happy with the pick up or mileage in the truck.

I live in Austin, tx and am mainly city driving up and down hills in NW austin so I am wondering if a gear change from 3.73LS to 4.10 would help me?

Thoughts?
Reply With Quote
  #12  
Old 08-13-2009, 08:03 AM
Senior Member
 
Join Date: Nov 2002
Location: Waco/Houston
Posts: 3,102
Quote:
Originally Posted by Austin FX4 View Post
Hi

I bought a used 2005 fx4 (50K miles) with 6 inch lift and it has 325/60/18 tires. I also added Custom 87 tunes (performance, tow, MPG) from VMP but am just not happy with the pick up or mileage in the truck.

I live in Austin, tx and am mainly city driving up and down hills in NW austin so I am wondering if a gear change from 3.73LS to 4.10 would help me?

Thoughts?
In your case I would go 4.56's....

I went 4.11's and I have smaller then factory diameter tires. I wish 4.30's were made for our 9.75 rear ends.
Reply With Quote
  #13  
Old 08-13-2009, 08:05 AM
Senior Member
 
Join Date: Nov 2002
Location: Waco/Houston
Posts: 3,102
Quote:
Originally Posted by Galaxy View Post
What he said^^^. I'm assuming you guys that suspect a loss have never actually done it?? I GAINED 1-2 everywhere, and have seen a best of 3 mpg increase. There are ZERO downsides from doing a gear change.

3.55 to 3.73 is NOT worth the cost or the effort for such a small change in ratio. You will not regret 4.10's. It completely transformed my truck across the board.
It's amazing all this mis-information on the internet from people who have not done it to their truck.

People to this day still don't beleive my truck was getting 21-22mpg before I installed my blower. Which on the highway I see anywhere from 17-19mpg. Depends on how fast I drive(70-85mph).
Reply With Quote
  #14  
Old 08-13-2009, 01:06 PM
Senior Member
 
Join Date: Aug 2008
Location: Douglasville GA
Posts: 4,778
I think these trucks should come with 4.10's out of the factory. They are the heaviest trucks out there but still have the same gears as the light weight 97-03's. Look at the Tundra's they come with 4.30's from the factory, and they perform really well compared to a comparable F150 with 3.55/3.73 gear ratio.
Reply With Quote
  #15  
Old 08-13-2009, 01:15 PM
glc
glc is offline
Senior Member
 
Join Date: Dec 2006
Location: Joplin MO
Posts: 33,570
They don't come with 4.10's because of the EPA gas mileage - which does not necessarily correspond with real world gas mileage.
Reply With Quote
 
 
Reply

Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
white elephant
Towing & Hauling
21
11-22-2016 10:34 AM
Willy 2.7
Introduction Forum
4
11-06-2015 10:39 PM
Bubbadewsky
Trucks For Sale (1997 - 2003)
0
09-29-2015 03:08 PM
2008_XL
Other Aftermarket
4
09-26-2015 07:06 PM
O2BNASHE
V8 Engines
6
09-26-2015 11:26 AM


Thread Tools
Search this Thread

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 On
Refbacks are Off



All times are GMT -4. The time now is 06:47 AM.