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 03-24-2014, 02:03 PM   #1
Senior Member
dennis45's Avatar

Join Date: Jun 2012
Location: BC
Posts: 4,680
The Secrets of Better Fuel Economy

Here is a Brochure by Cummins on the subject of Fuel Economy. Although it is directed toward Highway Trucks, there is some interesting reading for RV drivers also. Good bedtime reading.
This is what happens when a person has too much time on their hands searching the Internet.

What caught my eye was the part on Lubricants and comments about Synthetic Lubricants.


Dennis & Carol
2003, 4006, 41' DutchStar, Spartan, ISC 8.3L W/BanksPower - 2013 Honda CRV, BlueOx Baseplate, Aventa Bar & Patriot Brake. And the 04 Bird, Sunshine Car.
dennis45 is online now   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 03-24-2014, 06:56 PM   #2
Senior Member
Join Date: Feb 2012
Location: Baton Rouge, LA
Posts: 1,200

Thanks for the brochure.

Jim and Lynda, (Sophie, Jake, attack trained killer Shi-Tzus :-))

2003 Fleetwood Expedition 38N 2005 Saturn Vue
jlfbatonrg is offline   Reply With Quote
Old 03-24-2014, 09:05 PM   #3
Senior Member
89sandman's Avatar
Join Date: May 2012
Posts: 576
drive more downhill
89sandman is offline   Reply With Quote
Old 03-24-2014, 09:07 PM   #4
Senior Member
Ruddog's Avatar
Join Date: Nov 2013
Posts: 113
Great info. Thanks!
Ruddog is offline   Reply With Quote
Old 03-24-2014, 09:14 PM   #5
Senior Member
dons2346's Avatar
Country Coach Owners Club
Join Date: Dec 2010
Posts: 3,650
35,000 to 50,000 for tires to break in, wow.
dons2346 is offline   Reply With Quote
Old 03-25-2014, 05:21 AM   #6
Senior Member
Country Coach Owners Club
Retired Fire Service RVer's
Join Date: Feb 2013
Location: Ocala, Florida
Posts: 6,295
I also see the mpg changes with speed. When I set my cruise at 62, on the flats I get about 6.5 mpg, at 70 it drops to 5.5 to 6.0 mpg.

I did not realize the differences tires make at lower speeds. I guess I'm glad my tires are 3 to 4 years old, LOL! Tire pressures are important, for both mpg and load bearing.

Very eye opening report.
FMCA #F431170, GS #822128658, Escapees SKP #112655
2012 Airstream Mercedes Interstate Class B
Medico is offline   Reply With Quote
Old 03-25-2014, 05:56 AM   #7
Senior Member
Join Date: Jul 2013
Posts: 224
The part of the report that talks about ideal grading and operating RPM is particularly useful for the motorhome crowd, although we (as a group) cant configure the motorhome for ideal grading. For ideal operating RPM however, we can control that to some extent by choosing speed.

Toterhome with 80,000 GCWR, usually 65,000 as it rolls down the road.
At 62mph on the interstate: 7.4
At 65mph on the interstate: 7.8
At 68mph on the interstate: 7.6

Verified over a few thousand miles to equalize ambient conditions. The difference? It will not hold 12th gear (highest OD) at 62mph because its below peak torque/boost, which results in a drop to 11th gear. Sometimes 10th. At 65mph, while the drag is more, the time in highest gear is more.
2010 F150 King Ranch
2014 Forest River FR3
cucamelsmd15 is offline   Reply With Quote
Old 03-25-2014, 07:14 AM   #8
Senior Member
Kevin J's Avatar
Ford Super Duty Owner
Join Date: Nov 2012
Location: Indiana
Posts: 117
I found the very last item in the report to be interesting. Appendix C, which shows the "first fill" data. Is this saying that mpg is affected by "break-in" factors way up into the 100,000 to 140,000 mile range? If so, it seems to be a much greater factor on mpg than any of the previously mentioned items.
Maybe I misunderstand Appendix C.
2000 Rexhall Aerbus F53 Ford Chassis
Cheap Handling Fix, Five Star Tune
2005 Chevy Colorado Toad
Kevin J is offline   Reply With Quote
Old 03-25-2014, 08:47 AM   #9
Senior Member
plasma800's Avatar

Fleetwood Owners Club
Join Date: Nov 2013
Location: Houston, Texas
Posts: 2,998
Blog Entries: 1
I get crummy milage! I gotta read this
RVM#78 - -USAF- F-15 Eagle Radar Vet
2005 Fleetwood Revolution
'12 Chevy 2500HD
'15 Airstream International Signature 27FB
plasma800 is offline   Reply With Quote
Old 03-25-2014, 09:01 AM   #10
Senior Member
danes-on-tour's Avatar

Monaco Owners Club
Texas Boomers Club
Join Date: Feb 2008
Location: Denmark and US
Posts: 1,965
Originally Posted by dons2346 View Post
35,000 to 50,000 for tires to break in, wow.
Someone should tell that to Goodyear. My Goodyears were shot by 40,000.

Here is my promise to Goodyear: I will never again buy another Goodyear tire - ever.

The biggest factor for us is wind. Wind right on the nose is a mpg killer. Wind on the nose versus wind from the rear can make a difference as big as 4 mpg.
The Great Dane
2007 Monaco Diplomat PAQ - 2007 Saturn Vue Honorary Texas Boomer
Living in Denmark - visiting the US whenever possible. www.winnebago.dk www.blog.retired.dk

danes-on-tour is offline   Reply With Quote
Old 03-25-2014, 09:02 AM   #11
Senior Member
757driver's Avatar

Entegra Owners Club
Join Date: Jun 2004
Location: Cambridge, Ontario
Posts: 1,423
An interesting read, thanks Dennis.
Don & Gerri
2014 Entegra Anthem 44B
2014 Honda CRV Touring

FMCA F443497
757driver is offline   Reply With Quote
Old 03-25-2014, 02:43 PM   #12
Senior Member
Cat320's Avatar
Fleetwood Owners Club
American Coach Owners Club
Join Date: Mar 2011
Posts: 4,168
Originally Posted by danes-on-tour View Post
...The biggest factor for us is wind. Wind right on the nose is a mpg killer. Wind on the nose versus wind from the rear can make a difference as big as 4 mpg.
Agree, along with speed...they are the two biggest detriments to ''good'' mileage.
2014 American Eagle 45T
DD 500
Pulling a Honda CRV
Cat320 is online now   Reply With Quote
Old 03-25-2014, 02:47 PM   #13
RVM #74
PushedAround's Avatar

Tiffin Owners Club
Join Date: Sep 2012
Location: Ambler, PA
Posts: 2,849
Blog Entries: 7
Originally Posted by dons2346 View Post
35,000 to 50,000 for tires to break in, wow.
Yeah, just as they are getting hard & cracked for most of us, they start getting better mileage. It figures.
Larry & Cheryl Oscar, Louie, Ranger & Henry (our Springers)
2010 Allegro RED 38QBA "Harvey"
2009 Honda Element "Towster"
PushedAround is offline   Reply With Quote
Old 03-25-2014, 08:42 PM   #14
Senior Member
Ray,IN's Avatar
Join Date: Aug 2001
Location: North America somewhere
Posts: 12,300
Thank you Dennis. I too found the part about synthetic oils enlightening. That is proof enough for me to not uselessly spend money on synthetic motor oil.

2000 Winnebago Ultimate Freedom USQ40JD, ISC 8.3 Cummins 350, Spartan MM Chassis. USA 1SG, retired;PPA,Good Sam Life member."We the people are the rightful masters of both the Congress and the Courts - not to overthrow the Constitution but to overthrow men who pervert theConstitution. "Abraham Lincoln"
Ray,IN 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

Similar Threads
Thread Thread Starter Forum Replies Last Post
2005 Acert C13 low power and poor fuel economy slemnah Caterpillar Engine Forum 29 04-15-2014 04:26 PM
Entegra fuel economy Trose Entegra Owner's Forum 42 03-21-2014 04:16 AM
40% Better Fuel Economy - HYBRID Class A? Scarab0088 Class A Motorhome Discussions 4 10-03-2013 11:09 PM
Fuel Tank Problems Winnibago 78 Custom On Dodge chassis mdpeat Winnebago Industries Owner's Forum 6 07-25-2013 02:27 PM

» 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 06:51 PM.

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