Go Back   iRV2 Forums > MOTORHOME FORUMS > Class A Motorhome Discussions
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
Thread Tools Search this Thread Display Modes
Old 07-16-2013, 10:38 AM   #1
Junior Member
Join Date: Jul 2013
Posts: 4
Gear Ratios

Does anyone change out rear end gears to get better gas mileage? Posably go from 4:10 to 3:90s

rababk is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 07-16-2013, 01:41 PM   #2
Senior Member
Skip426's Avatar

Join Date: Apr 2011
Location: Powell River, B.C.
Posts: 11,954
Changing out a gear set could , marginally improve fuel economy , but the increase could be so slight that verses the cost of the gears it might never be repaid in fuel savings .
The drop in acceleration rate, downshifting to climb hills instead of holding a higher gear.
The 2 major factors in diesel MH fuel economy are driver habits and route selection. A light foot and staying on major highways to maintain a reasonable cruising speed will get the best mileage.
Any savings from the slight ratio change your suggesting could be accomplished by slowing cruising speed by 3>5 mph , achieving the same cruise RPM drop.

99DSDP 3884, Freightliner, XC, CAT 3126B, 300 HP /ALLISON 3060
2000 Caravan toad, Remco & Blue Ox.
Skip426 is offline   Reply With Quote
Old 07-16-2013, 05:38 PM   #3
Junior Member
Join Date: Jul 2013
Posts: 4
Thank You
Good advise.
rababk is offline   Reply With Quote
Old 07-17-2013, 07:50 AM   #4
Senior Member
bailiff's Avatar
Join Date: May 2013
Posts: 381
Just my 2 cents... I had a 1994 Chevy 2500 Z-71 with a 3:73 rear and 350. It pulled my 18' enclosed trailer great. In 1997, I ordered a 1998 2500 Z-71 350 but had ordered the rear gear, (I think it was) 3:42 rear, thinking of a more fuel efficient vehicle. Without the trailer, the truck was fine but fuel milage didn't improve very much if any. The sad part, I had to pull my trailer in D instead of OD. In OD, it would shift down on interstate overpasses. After 22,000 miles, I traded it off.
bailiff is offline   Reply With Quote
Old 07-17-2013, 05:28 PM   #5
Senior Member
Rich and Cork's Avatar
Join Date: Jan 2006
Posts: 1,020
Here is another solution:

Gear Vendors under/overdrive transmissions the most awarded auxiliary transmissions.
2001 34' Alpine Coach
2008 Jeep Rubicon or 2012 Ford F150 4x4 Lariat towds
or a couple of different trailers
Retired in Apple Valley, California
Rich and Cork is offline   Reply With Quote
Old 07-18-2013, 10:42 AM   #6
Senior Member
Join Date: Nov 2005
Posts: 3,049
I believe the most common gear ratio on the F53 chassis is 5.38. A few years ago Ford started making different gear ratios depening on the weight the rear axle was rated to carry. The ratios for the 2013 and 2014 models are:

The 11,000 and 12,000 lb rear axles have a 4.30 gear ratio

The 13,000 and 15,000 lb rear axles have a 5.38 gear ratio

The 17,500 lb rear axle has a 6.17 gear ratio

2013 Adventurer 32H
Hikerdogs is offline   Reply With Quote

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

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

» Virginia Campgrounds

Reviews provided by

Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities

Copyright 2002-2015 Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 06:57 AM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, vBulletin Solutions, Inc.