|
07-22-2020, 05:22 PM
|
#1
|
Rivet Master
Currently Looking...
Sioux Falls
, South Dakota
Join Date: Mar 2011
Posts: 1,183
|
Axle ratios
We're temporarily off the road, and I'm starting to seriously look for a pickup. We've narrowed things down to 2013-2017 Ford and RAM diesels, mainly because of a relationship with the local dealer. What rear axle ratios should I prefer? Which ones should I avoid? This is the first time I've ever had to be concerned about that number. I know that the lower the number the better fuel economy but the poorer pulling power, and the higher the number the better pulling power but poorer fuel economy. What's the best compromise?
__________________
David Lininger, kb0zke
AIR 54240
Heartland mpg 181 (sold)
1993 Foretravel U300 (sold)
2022 Grand Design Reflection 315RLTS
|
|
|
07-22-2020, 05:34 PM
|
#2
|
Rivet Master
1977 23' Safari
Niagara on the Lake
, Ontario
Join Date: Aug 2011
Posts: 984
|
Axle ratio is only one part of the equation. tire size, transmission gearing and peak horsepower and torque will affect towing as much as axle ratio.
__________________
1977 Safari Land Yacht
2005 Toyota Tundra SR5
2022 Toyota 4Runner SR5
|
|
|
07-22-2020, 08:26 PM
|
#3
|
Rivet Master
Currently Looking...
Sioux Falls
, South Dakota
Join Date: Mar 2011
Posts: 1,183
|
Agreed. Specifically, I'm looking at the diesel engine and automatic transmission versions of each truck. Most of what I'm finding are 4wd models. As I understand things, the original buyers can choose from several different rear ends to increase either pulling power or fuel economy. I suspect that most trucks, though, come with the standard one. This question is probably aimed more at the gearheads out there. For example, I'm looking at a pair of F250's. One has a 3.73 rear axle and LT235/85R16E tires. The other has 3.31 rear axle and LT265/70RX17E tires. Any preference just based on rear axle and tires?
__________________
David Lininger, kb0zke
AIR 54240
Heartland mpg 181 (sold)
1993 Foretravel U300 (sold)
2022 Grand Design Reflection 315RLTS
|
|
|
07-22-2020, 08:54 PM
|
#4
|
Rivet Master
2017 28' International
Jim Falls
, Wisconsin
Join Date: Jul 2017
Posts: 2,310
|
Frankly, you won’t need to worry. Any 3/4 ton diesel can pull an Airstream with ease. The lower the axle ratio the less towing capacity, but the better the gas mileage. The higher the ratio the more towing capacity and less towing capacity. If you can find one with a 3.2 to 3.5 I would go with that. Unless you are pulling something 15,000lbs or more you don’t need anything different. I would go with the 3.31 for an Airstream; better gas mileage.
|
|
|
07-22-2020, 09:16 PM
|
#5
|
Rivet Master
2014 27' Flying Cloud
Wenatchee
, Washington
Join Date: May 2014
Posts: 512
|
My ‘12 Ram 3500 came with 3.73 gears and my ‘18 Ram 3500 came with 3.42’s. The ‘18 has more power and gets 50% better fuel economy. (The Big 3 truck companies seem to be making them more and more efficient.).
I agree, ANY 250/2500 can tow an Airstream snd the newer the better.
__________________
2018 Ram 3500 SLT CTD 4X4 pickup
2014 Airstream Flying Cloud 27FB
WBCCI #7180
|
|
|
07-22-2020, 09:39 PM
|
#6
|
2 Rivet Member
2005 28' Safari
Mono City
, California
Join Date: Dec 2007
Posts: 66
|
The 2013 to 2017 Ford 6.7L Diesels are having failures of the High Pressure Fuel Pump
CP-4. Check out this problem on the internet. The Cummins in the Ram use a different High Pressure Pump and are not having failures. The CP-4 pump was used on the Duramax from 2011 to 2016 and are failing. Cost of repairs for the failure runs from $10,000 to $15,000.
|
|
|
07-23-2020, 05:10 AM
|
#7
|
"Cloudsplitter"
2003 25' Classic
Houstatlantavegas
, Malebolgia
Join Date: Jun 2007
Posts: 20,000
|
Axle ratios today are a lot less important, they are just one part of the powertrain.
The engineers have done a much better job of designing the powertrain to optimize economy & performance.
You have a lot of ratios with an 8,9 or 10 speed transmission.
Bob
🇺🇸
__________________
I’m done with ‘adulting’…Let’s go find Bigfoot.
|
|
|
|
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
|
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
Similar Threads
|
Thread |
Thread Starter |
Forum |
Replies |
Last Post |
Tahoe Axle Ratios
|
RivaHaven |
Towing, Tow Vehicles & Hitches |
0 |
10-06-2015 12:56 PM |
rear axle ratios
|
rosser7 |
Towing, Tow Vehicles & Hitches |
3 |
08-19-2012 11:27 AM |
Weight Ratios?
|
Bluto |
Hitches, Couplers & Balls |
34 |
10-05-2010 10:00 PM |
gear ratios
|
ixnaycraig |
Mechanics Corner - Engines, Transmission & More... |
6 |
11-16-2008 10:06 PM |
gear ratios
|
RVNUTTY |
Tow Vehicles |
11 |
09-04-2004 03:38 PM |
|
Recent Discussions |
|
|
|
|
|
|
|
|
|
|
|