Go Back   iRV2 Forums > MOTORHOME FORUMS > Class A Motorhome Discussions
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 08-18-2009, 05:55 PM   #15
RV Mutant #14
 
Wayne M's Avatar


 
Winnebago Owners Club
Texas Boomers Club
Freightliner Owners Club
iRV2 No Limits Club
Join Date: Aug 2008
Location: Texas
Posts: 12,188
Hmmm! Guess I should be happy with my ISB 6.7, FLC, Winne Destination's 8.9 average on my last 4000 mile trip. Thanks all.
__________________

__________________
Wayne MSGT USMC (Ret) & Earlene (CinCHouse)
2015 Winnebago Tour 42QD
RVM14
It is what it is, and then it is what you make of it.
Wayne M 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 08-21-2009, 07:49 PM   #16
Senior Member
 
GaryKD's Avatar
 
Newmar Owners Club
Join Date: Jul 2006
Location: Wellington, Florida
Posts: 12,314
Hi sleprr,
This is another vote for Stanadyne Performance Formula (they have quite a few products). It comes in a clear bottle with a blue label. I have over 10K mile using this product and gained a little over 1 MPG. The coach has 54K miles, Cummins ISC, coach weighs 32K and I am towing 5725 lbs. Both coach and toad were just four corner weighed. I travel 60 MPH on interstate highways. Stanadyne Performance Formula has kept my overall mileage at 8.6 MPG (it was a consistent 7.4).

Unfortunately, Cummins made a mandatory change to my exhaust system and after 2.2K miles I have lost 6/10 MPG. The fall trip is coming up and that will provide an additional 3.5K miles on the exhaust system. Time will tell if I can get the 8+ MPG back.

Another thought is altitude. I think for every 1K in elevation one loses 5% of the available HP. I know my ISC does not like the Rocky Mountains. Over 5K feet in elevation I really notice a drop in power. Above 12K feet in elevation and the ISC is searching for oxygen. She really slows down. Fuel mileage suffers greatly.
__________________

__________________
Gary
2005 Newmar KSDP 3910 + GMC ENVOY XUV 37K lbs Moving Down The Road
The Avatar Is Many Times Around The USA
Nobody Knows Your Coach Like Somebody Who Owns One Just Like Yours
GaryKD is offline   Reply With Quote
Old 08-22-2009, 09:40 AM   #17
Moderator Emeritus
 
Gary RVRoamer's Avatar


 
Join Date: Jan 2000
Location: Silver Springs, FL. USA
Posts: 18,066
Quote:
Another thought is altitude. I think for every 1K in elevation one loses 5% of the available HP. I know my ISC does not like the Rocky Mountains. Over 5K feet in elevation I really notice a drop in power.
That's unusual for any turbo-diesel. The turbo boost can normally supply plenty of air, enough so the thinner air is no problem. If mine did that at 5000, I would be wondering if my turbo was working properly. I seen no lack of power up to 8000 ft. with my ISL.
__________________
Gary Brinck
Former owner of 2004 American Tradition
Home is in the Ocala Nat'l Forest near Ocala, FL
Summers in Black Mountain, NC
Gary RVRoamer is offline   Reply With Quote
Old 08-23-2009, 06:39 AM   #18
Senior Member
 
Triker56's Avatar
 
Fleetwood Owners Club
Join Date: Jun 2009
Posts: 3,946
The rule of thumb is a 3 percent loss of power for every 1,000 feet of elevation for a normally aspirated gas engine.

Once you get a Diesel turbo spun up there should be very little loss in HP. One could have loss of HP if the wastegate or turbo isn't working like it should.

The Diesel has the same HP as at sea level but pushing all the weight up a hill it uses more of it and a little more fuel. But coming down the other side of that hill you should be using very little or no fuel.
__________________
99 Discovery 34Q ISB
2014 MKS AWD EcoBoost Toad
Fulltime Since "99"
Triker56 is offline   Reply With Quote
Old 08-23-2009, 07:31 AM   #19
Junior Member
 
2pedersens's Avatar
 
Join Date: Mar 2009
Posts: 17
I think most people with large motorhomes,towing cars and claiming 9 and 10 mpg are going downhill with a tail wind. I get 7.5 to 8 mpg on my 06 Diplomat 40 ft motor home with a 400 Cummins engine towing a Jeep Grand Cherokee going 62 to 65 mph overall. It has 27000 miles on it and has been serviced and checked out on a regular basis. I would not expect more out of a motorhome this size. Power wise, it recently got me over the passes thru Glacier and hardly noticed the hills.

Neil
__________________
2pedersens is offline   Reply With Quote
Old 08-23-2009, 09:01 AM   #20
Senior Member
 
Elkhartjim's Avatar


 
Newmar Owners Club
Texas Boomers Club
Freightliner Owners Club
Join Date: Jul 2008
Location: Don't mess with Texas
Posts: 3,116
Quote:
Originally Posted by 2pedersens View Post
I think most people with large motorhomes,towing cars and claiming 9 and 10 mpg are going downhill with a tail wind. I get 7.5 to 8 mpg on my 06 Diplomat 40 ft motor home with a 400 Cummins engine towing a Jeep Grand Cherokee going 62 to 65 mph overall. It has 27000 miles on it and has been serviced and checked out on a regular basis. I would not expect more out of a motorhome this size. Power wise, it recently got me over the passes thru Glacier and hardly noticed the hills.

Neil
Now now Neil, you know darn well we get over 11 mpg when going down hill with a good strong tail wind. Now let me tell you about going uphill with a strong head wind.
__________________
Jim with Judy
2017 Newmar Ventana 4369, 2005 Jeep Wrangler (Rock Crawler), 2016 Jeep Wrangler (Mall Crawler)
Elkhartjim is offline   Reply With Quote
Old 08-23-2009, 09:10 AM   #21
Senior Member
 
Korryp's Avatar
 
Fleetwood Owners Club
Freightliner Owners Club
Join Date: Feb 2008
Location: Sammamish, WA
Posts: 159
Quote:
Originally Posted by 2pedersens View Post
I think most people with large motorhomes,towing cars and claiming 9 and 10 mpg are going downhill with a tail wind. I get 7.5 to 8 mpg on my 06 Diplomat 40 ft motor home with a 400 Cummins engine towing a Jeep Grand Cherokee going 62 to 65 mph overall. It has 27000 miles on it and has been serviced and checked out on a regular basis. I would not expect more out of a motorhome this size. Power wise, it recently got me over the passes thru Glacier and hardly noticed the hills.

Neil
I have an 07 Bounder Turbo Diesel that when not towing achieves 9.2 MPG. Towing is 8.3 MPG. I still hope that with an additional 10K-20K miles it may get better.
__________________
'07 Fleetwood Bounder Diesel 38N
Brazel's added: MP-8, Aero Muffler, Koni FSD Shocks, Bell Crank and Comfort Ride Control Valves. '08 Ford Escape Hybrid, Brakemaster 9100
Korryp is offline   Reply With Quote
Old 08-23-2009, 01:05 PM   #22
Senior Member
 
Monaco38's Avatar
 
Monaco Owners Club
Join Date: Jul 2009
Posts: 172
Regarding fuel additives, is it advisable to use fuel additives in diesel fuel to inhibit algae growth and deal with fuel tank condensation in rigs that are not used on a full time basis. I am concerned that these two issues in particular will be a problem as we will not be using our motor home on a regular basis through the winter. If additives are advised what have others found that works well in dealing with microbes and moisture?
__________________

__________________
Jerry & Barb ~ Furbies: Dylan, Daisy, Brandee, Finnegan
2003 Monaco Camelot 38PST, Cummins 350 ISC, Roadmaster RR8S chassis, 2004 Honda CR-V Toad, FMCA, Olympia, WA K7DKO

Monaco38 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
The Off-Topic Thread MonacoMama Excel Owner's Forum 3405 04-26-2017 12:11 PM
Synthetic lubricants-Aren't??? RV Roadie iRV2.com General Discussion 44 10-15-2014 07:25 PM
Lucas Fuel Treatment Digital Boy Cummins Engines 21 06-29-2009 07:55 AM
Gas Additives - RxP Jeff_E Gear and Product Discussions 2 07-14-2008 02:17 AM
Diesel Lubricity Additive Info EngineerMike Alpine Coach Owner's Forum 17 12-10-2007 08:47 AM

» Virginia Campgrounds

Reviews provided by


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 10:54 AM.


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