Go Back   iRV2 Forums > TRAVEL TRAILER, 5th WHEEL & TRUCK CAMPER FORUMS > Trailer Towing and Tow Vehicles Discussion
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Reply
  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 02-27-2014, 08:28 AM   #15
Senior Member
 
MoeBelly's Avatar
 
Forest River Owners Club
Join Date: Jan 2014
Location: Pittsburgh, PA
Posts: 388
With newer 6-speed transmissions available on TVs, fuel economy has been found to be not a significant issue when lowering gear ratio. I can see an issue when you are travelling at fast speeds but for towing I would not be going over 65-70mph anyway. If a lower ratio is available for your truck, I say go for it.

Understanding Axle Ratios | Medium Duty Work Truck Info
__________________

__________________
Dan (RVM67), Yvonne & 2 nutty mutts
2015 Flagstaff V-Lite 30WFKSS; 2012 Sierra 2500HD Crew
Home is behind, the world ahead, and there are many paths to tread...
MoeBelly 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 02-27-2014, 09:38 AM   #16
Moderator Emeritus
 
SmokeyWren's Avatar


 
Join Date: Jun 2011
Location: Midland County, Texas
Posts: 3,326
Quote:
Originally Posted by D Lindy View Post
Sorry but 3.36:1 gears are not towing gears, they're highway gears meant to get maximum MPG and are not for towing.
Granted, but that's the lowest ratio (higher numerically) available for a Titan, and presumably for an Armada. Randy's does not offer ring gear and pinion sets for an Armada, but I'll bet the one for a Titan will fit in the Nissan differentials.

The 2014 Armada specs say that with a weight-distributing hitch, the SL and Platinum trim 4x4s have a max towing capacity of 9,000 pounds. Of course that's max, with nothing in the SUV except a skinny driver. No passengers, no pets, no tools, nothing. Real-world max towing capacity without exceeding the GVWR of the SUV, or the max hitch weight of the optional WD hitch of 900 pounds, will be closer to 7,000 pounds. That would be 12.86% hitch weight, which is about average for a wet and loaded TT. (My TT has 15% hitch weight).

Optional tow mirrors and WD hitch are available for the Armada from Nissan dealers, but no mention of optional axle ratios or towing packages. On the Titan, there is a max utility package that includes: "Lower final gear ratio (3.36:1)". So apparently that's as low as they go from the Nissan factory.
__________________

__________________
SmokeyWren is offline   Reply With Quote
Old 03-02-2014, 01:46 PM   #17
Member
 
CanadianCrew's Avatar
 
Join Date: Jun 2002
Location: Ontario, Canada
Posts: 97
Quote:
Originally Posted by MoeBelly View Post
With newer 6-speed transmissions available on TVs, fuel economy has been found to be not a significant issue when lowering gear ratio. I can see an issue when you are travelling at fast speeds but for towing I would not be going over 65-70mph anyway. If a lower ratio is available for your truck, I say go for it.

Understanding Axle Ratios | Medium Duty Work Truck Info
Yes good point. Its a little easier when gearing to keep the motor in the rpm and torque you wish with a 6 speed. In the days of 3 speeds the rpm range through 3rd gear was hugh.
__________________
2013 Salem Cruise Lite 221RBxl
06 GMC
CanadianCrew is offline   Reply With Quote
Old 03-02-2014, 03:27 PM   #18
Senior Member
 
DavisK's Avatar
 
Thor Owners Club
Join Date: Feb 2014
Posts: 204
Quote:
Originally Posted by SmokeyWren View Post
The 2014 Armada specs say that with a weight-distributing hitch, the SL and Platinum trim 4x4s have a max towing capacity of 9,000 pounds. Of course that's max, with nothing in the SUV except a skinny driver. No passengers, no pets, no tools, nothing. Real-world max towing capacity without exceeding the GVWR of the SUV, or the max hitch weight of the optional WD hitch of 900 pounds, will be closer to 7,000 pounds. That would be 12.86% hitch weight, which is about average for a wet and loaded TT. (My TT has 15% hitch weight).

Optional tow mirrors and WD hitch are available for the Armada.
Those optional mirrors would probably make it over weight.
__________________
2013 Silverado 2500 HD LTZ CC 6.6L Duramax Diesel
2014 Sunset Trail SF270BH
Holly & Buster, mini Dachshunds
DavisK is offline   Reply With Quote
Old 03-03-2014, 03:00 PM   #19
Senior Member
 
TDI-Minnie's Avatar
 
Join Date: Sep 2013
Posts: 1,733
Just a thought, but the easiest option would be to go on Tirerack or similar website and order some cheap wheels with lower tires. This will help lower your TV's center of gravity and improve handeling/aerodynamics. Will achieve your gearing improvment and actually make your brakes a lot stronger.
Tires don't need to be any narrower, just shorter aspect ratio.

You can just get the tires mounted on your OEM wheels, but I think it's a lot easier to just swap the wheels when needed. That way you can easily got back to the correct gearing for the 95% of the time you are not towing.

You will also benefit from less rotating mass, so fuel economy and performance should be great!

If you don't like, just sell them on ebay.
__________________
2013 Winnebago 2301BH-Red
2012 Ram 2500 Megacab HO CTD
TDI-Minnie is offline   Reply With Quote
Old 03-04-2014, 07:19 AM   #20
Member
 
CanadianCrew's Avatar
 
Join Date: Jun 2002
Location: Ontario, Canada
Posts: 97
Quote:
Originally Posted by TDI-Minnie View Post
Just a thought, but the easiest option would be to go on Tirerack or similar website and order some cheap wheels with lower tires. This will help lower your TV's center of gravity and improve handeling/aerodynamics. Will achieve your gearing improvment and actually make your brakes a lot stronger.
Tires don't need to be any narrower, just shorter aspect ratio.

You can just get the tires mounted on your OEM wheels, but I think it's a lot easier to just swap the wheels when needed. That way you can easily got back to the correct gearing for the 95% of the time you are not towing.

You will also benefit from less rotating mass, so fuel economy and performance should be great!

If you don't like, just sell them on ebay.
You can't do that on today's computerized trucks. Yes it did work back on the 1972 chevy. Here is a quote from a tire site.

Here’s the basic issue: Your speedometer, odometer, traction control, torque and gearing settings are all based on the distance that your tire travels over one complete revolution, which is determined by the outside diameter of the tire-and-wheel assembly. A tire with a different outside diameter will travel a different distance over that one revolution with a different amount of torque.
So, when changing the diameter of your rims, you must make sure that the new wheel and tire assembly keeps the same overall diameter as the old, or your speedometer will be showing you the wrong speed and your traction control settings will be off.
__________________
2013 Salem Cruise Lite 221RBxl
06 GMC
CanadianCrew is offline   Reply With Quote
Old 03-04-2014, 08:04 AM   #21
Senior Member
 
caissiel's Avatar
 
Join Date: Oct 2011
Posts: 1,312
My programmer that I would not be without takes care of different size tires and wheels.
__________________
Barbara and Laurent, Hartland Big Country 3500RL. 39 ft long and 15500 GVW.
2005 Ford F250 SD, XL F250 4x4, Long Box, 6.0L Diesel, 6 Speed Stick, Hypertech Max Energy for Fuel mileage of 21 MPusG empty, 12.6 MPusG pulling the BC. ScangaugeII for display..
caissiel is offline   Reply With Quote
Old 03-04-2014, 11:29 AM   #22
Senior Member
 
BFlinn181's Avatar
 
Gulf Streamers Club
Join Date: Jan 2012
Location: Cincinnati
Posts: 16,208
Quote:
Originally Posted by CanadianCrew View Post
You can't do that on today's computerized trucks. Yes it did work back on the 1972 chevy. Here is a quote from a tire site.

Here’s the basic issue: Your speedometer, odometer, traction control, torque and gearing settings are all based on the distance that your tire travels over one complete revolution, which is determined by the outside diameter of the tire-and-wheel assembly. A tire with a different outside diameter will travel a different distance over that one revolution with a different amount of torque.
So, when changing the diameter of your rims, you must make sure that the new wheel and tire assembly keeps the same overall diameter as the old, or your speedometer will be showing you the wrong speed and your traction control settings will be off.
"Today's computerized trucks" makes changing wheel diameter easier than ever. Instead of needing a new speedometer head you simply reprogram the computer.
__________________

Bob & Donna
'98 Gulf Stream Sun Voyager DP being pushed by a '00 Beetle TDI
BFlinn181 is online now   Reply With Quote
Old 03-04-2014, 11:33 AM   #23
Moderator Emeritus
 
SmokeyWren's Avatar


 
Join Date: Jun 2011
Location: Midland County, Texas
Posts: 3,326
Quote:
Originally Posted by CanadianCrew View Post
You can't do that on today's computerized trucks.
Yes you can, on most tow vehicles. But you have to do some computer program changes.

Quote:
Here’s the basic issue: Your speedometer, odometer, traction control, torque and gearing settings are all based on the distance that your tire travels over one complete revolution, which is determined by the outside diameter of the tire-and-wheel assembly. A tire with a different outside diameter will travel a different distance over that one revolution with a different amount of torque.
So if you mount tires that have a different tire revolutions per mile (revs/mile or TRPM), then you have to reprogram the applicable computer module in your tow vehicle to change the TRPM to match your new tires. Most new tires include the revs/mile in their specs.

For example, on a Ford SuperDuty, the TRPM is stored in the ABS module (computer), not in the main computer (Powertrain control module or PCM). A good computer guru can go into the software inside ABS module and change the TRPM parameter to whatever is required. Most Ford techs can do it also, using the Ford diagnostic system, but on the newer trucks they are limited to the tire sizes that were available on that truck as standard or optional equipment from the factory.

There are also "black boxes" available to the general public that will allow you to change the TRPM in your tow vehicle's computer. These are the "programmers" that are primarily used to increase power, but some includes gauges, diagnostics, and even speedo adjustment. If you adjust the speedo, that takes care of all the other functions that rely on the TRPM.

However, I don't see an Edge Evolution programmer available for a Nissan of any kind, much less an Armada. So maybe some other brand of programmer, or a guru of a Nissan tech that knows how to adjust the speedo on an Armada.

And there is computer software available for use on a laptop, usually used for diagnostics but some of it also includes speedo adjustment. Any good off-road center that sells lots of big tires and lifts will probably have such software available. You can buy it yourself, but not cheap. Here's the best one for Ford vehicles:
90068 NGS PC Software Solution Kit

There are also hand-held diagnostic tools (scanners) available that include the ability to adjust the speedo. Those were a required tool in any mechanic's tool box a decade ago, but by now most have been replaced with laptops or tablets with diagnostic software. But they're still available to pros that want them. Here's the most popular with Ford techs:
Hickok, Inc. - For Your Quality Automotive Diagnostic Equipment Needs

Quote:
So, when changing the diameter of your rims, you must make sure that the new wheel and tire assembly keeps the same overall diameter as the old, or your speedometer will be showing you the wrong speed and your traction control settings will be off.
UNLESS you change the TRPM in your tow vehicle's computer systems.
__________________
SmokeyWren is offline   Reply With Quote
Old 03-04-2014, 12:33 PM   #24
Senior Member
 
Ford Super Duty Owner
Join Date: Jan 2011
Location: Kitts Hill, OH
Posts: 1,863
one more thing many don't know about gears and gear reductions.
is Torque at the axles and traction.
Ever wonder how high the torque can get at the rear axles? just take the max torque number form your engine and multiply it by you first gear ratio and multiply that by you rear axle ratio.
My "RV" has a 6 speed trans with pretty even gear spacing. I first swapped to a higher gear ratio while I was building it. Doing the math showed basically a hill you could climb in say 4th gear you would now be in 3rd. And that is exactly what it felt like.
I drove it this way on my first trip. The next year I turn up the injector pump. didn't replace any parts just slid the Fuel plate inside the top of the pump. moved the smoke screw 4 clicks. (there is no visible smoke unless you are above 6k feet and NOT under boost) under boost there is NO smoke at any altitude.
This is supposed to be Fords 230HP setting (+40HP & +130TQ over stock.)
MPG didn't change at all with the power bump. I belive it it because grades I climbed in 4th gear at 2500 RPM I now climbed in 5th at 1900 RPM

Here is the math on the gear ratio change.
Mine as is now.
605 engine torque X 9.01(First gear)=5451 X 3.58 (rear axle)=19,514 foot pounds at the rear axles
in high gear (1:1) its this 605 X 3.58= 2165 foot lbs
---------------------------------------------------------------------------------
What it had as a Medium Duty Truck (Top speed was a bout 55 MPH and loud)
475 X 9.01= 4279.75 X 5.29 = 22639.87 1st gear
high gear 475 X 5.29 = 2512 foot lbs
__________________
(RVM#26) THE U-RV 94 F-700/24 foot U-haul box home built RV
Mekanic is offline   Reply With Quote
Old 03-05-2014, 08:16 AM   #25
Senior Member
 
TDI-Minnie's Avatar
 
Join Date: Sep 2013
Posts: 1,733
The changing of tire size only requires anything if you want to correct a slight speedo error. So it may indicate 70 instead of 65mph. As long as all four are the same size and turning at the same speed, it will have no effect because the car has no idea.
There is nothing you will have to do and all systems will work as before.

And anyone that borrows your car will actually drive slower. LOL
__________________
2013 Winnebago 2301BH-Red
2012 Ram 2500 Megacab HO CTD
TDI-Minnie is offline   Reply With Quote
Old 03-05-2014, 10:42 AM   #26
Moderator Emeritus
 
SmokeyWren's Avatar


 
Join Date: Jun 2011
Location: Midland County, Texas
Posts: 3,326
Quote:
Originally Posted by TDI-Minnie View Post
So it may indicate 70 instead of 65mph.
You've got it bass ackwards. Taller tires result in a slower speedo. So with a typical 8.4% decrease in tire revs/mile (change from 655 to 600 revs/mile, or approximately 32" diameter to 35"diameter tires), your speedo showing 70 MPH will be an actual speed of 75.9 MPH on Officer Bob's radar gun. I hate speeding tickets, so I'm very insistent on having my speedo calibrated to less than one MPH speedo error.

It's relatively easy to calibrate the speedo on most vehicles, even on the newer Fords. In the older Fords such as my '99.5 F-250, it was really easy. All you needed was a $2,500 NGS scanner and a tiny bit of knowledge of how to use the scanner to change the revs/mile parameter in the ABS module. Fortunately, my Ford dealer had the NGS, and I taught a local Ford tech how to use it to change the revs/mile parameter in the ABS module.

On most brands, you can use even a cheap scanner that costs less than $400 to calibrate the speedo. But on a Ford you must have the special Ford version of the scanner software to access the ABS module.
__________________
SmokeyWren is offline   Reply With Quote
Old 03-05-2014, 11:12 AM   #27
Senior Member
 
BFlinn181's Avatar
 
Gulf Streamers Club
Join Date: Jan 2012
Location: Cincinnati
Posts: 16,208
Quote:
Originally Posted by TDI-Minnie View Post
The changing of tire size only requires anything if you want to correct a slight speedo error. So it may indicate 70 instead of 65mph. As long as all four are the same size and turning at the same speed, it will have no effect because the car has no idea.
There is nothing you will have to do and all systems will work as before.

And anyone that borrows your car will actually drive slower. LOL
Quote:
Originally Posted by SmokeyWren View Post
You've got it bass ackwards. Taller tires result in a slower speedo. So with a typical 8.4% decrease in tire revs/mile (change from 655 to 600 revs/mile, or approximately 32" diameter to 35"diameter tires), your speedo showing 70 MPH will be an actual speed of 75.9 MPH
SmokeyWren, TDI-Minnie made no mention of LARGER tires, in fact TDI-Minnie, in post #19 talked smaller tires. and most of this thread has been assuming the OP wanted to increase rear axle ration to provide more pulling power, which would be accomplished by REDUCING tire diameter, thus resulting in higher speedo readings. As stated a number of times, this can be corrected by reprogramming the ECU.
__________________

Bob & Donna
'98 Gulf Stream Sun Voyager DP being pushed by a '00 Beetle TDI
BFlinn181 is online now   Reply With Quote
Old 03-05-2014, 06:39 PM   #28
Moderator Emeritus
 
SmokeyWren's Avatar


 
Join Date: Jun 2011
Location: Midland County, Texas
Posts: 3,326
Quote:
Originally Posted by BFlinn181 View Post
SmokeyWren, TDI-Minnie made no mention of LARGER tires, ...
You're right. My bad. Blame it on CRS. In my world, nobody ever asks about mounting smaller tires with less diameter (and less weight carrying capacity).
__________________

__________________
SmokeyWren is offline   Reply With Quote
Reply



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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Journey 40U rear axle capacity D Lindy Winnebago Industries Owner's Forum 33 11-20-2014 09:05 AM
Rear Axle weight limit solution D Lindy Winnebago Industries Owner's Forum 5 02-02-2014 06:56 AM
Looking for Input on Side vs Rear Radiator XCR Chassis Pusherdiva Freightliner Motorhome Chassis Forum 13 12-10-2013 08:32 PM
Axle weights, few questions smlranger Country Coach Owners Forum 8 06-20-2013 08:42 PM
Squirrely rear camera RJEV MH-General Discussions & Problems 8 06-08-2013 04:39 PM

» Virginia Campgrounds

Reviews provided by


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 10:22 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.