Journey with Confidence RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Take a Speed Test Free 7 Day Trial ×
RV Trip Planning Discussions

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.
  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 05-23-2022, 04:20 AM   #1
Junior Member
Join Date: Sep 2011
Posts: 12
How can I improve gas mileage - Damon Intruder 367

We have a 2004 Damon Intruder 367 with a Ford V-10 gas engine, mileage on unit is about 37,500. I have been getting 7 to 7.5 mpg in the mountains and 8 to 8.5 mpg on flat land here in Colorado.
This was towing a dolly with a Ford Escort on it. I will now be towing a 2001 Jeep Grand Cherokee on all 4 wheels {5200 lbs}.
My speed was at 70 MPH, tried 55 to 60 MPH and mileage went down.
Does anyone have any ideas?
We are planning a 6000 to7000 mile trip this year.
Wolf-S is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free! 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 05-23-2022, 05:05 AM   #2
Senior Member
Join Date: Jan 2022
Posts: 248
Well, to start the Jeep does not weigh 5200lbs, more likely 4500.
Not sure how you were getting 8mpg at 70 mph? My 12 with the 5 speed towing my Explorer gets 7 at best!
I think you may need to rerun your numbers! Even my 02 V-10 Excursion towing a 35ft TT would only do 7!
Dodge Guy is offline   Reply With Quote
Old 05-23-2022, 05:10 AM   #3
Senior Member

Holiday Rambler Owners Club
Join Date: Aug 2015
Posts: 5,984

I drive 62 mph on mostly-flat terrain, tow an under-3000-pound vehicle four-down, and do well to get mpg better than 7.5. Typical mpg is 7.

I believe your coach has a four-speed transmission. Mine has the five-speed.

I am surprised that your coach's mileage decreased when you slowed down. I would expect an improvement of 20 percent or so when slowing from 70 to 55 mph.

I'm sorry to say that I can't offer any help, just commiseration.
2008 Holiday Rambler Admiral 30PDD (Ford F-53 chassis)
2009 Honda Fit Sport
l1v3fr33ord1 is online now   Reply With Quote
Old 05-23-2022, 07:26 AM   #4
Senior Member
Join Date: Dec 2013
Location: Lake Havasu City, AZ & Plover, WI
Posts: 5,437
Something doesn't sound right. I have never heard of a box shaped vehicle getting better mileage at 70 mph than at 55-60 mph.
Of the seven motorhomes I have owned in 25 years, all of them had improved economy when driving 60 vs 70. Sorry, I don't know how to respond.
2013 43 QGP Allegro Bus
2013 Avalanche
2000 AEV TJ
Crasher is offline   Reply With Quote
Old 05-23-2022, 07:46 AM   #5
Senior Member
Workhorse Chassis Owner
Join Date: Jul 2005
Location: USA
Posts: 3,129
One can drive so fast that to battle air resistance more downshifting occurs.
One can drive too slow and downshifting occurs due to loss of torque. Most vehicles have a torque range suitable for traveling approximately 60 MPH. Your results may differ as you try to find the point at which high gear predominates.
TandW is online now   Reply With Quote
Old 05-23-2022, 08:02 AM   #6
Senior Member
edgray's Avatar
Join Date: Oct 2002
Location: Madison, MS
Posts: 10,072
Wolf- S
IF the Jeep weighs more than 4000 pounds you MAY be exceeding the GCVWR of your chassis, depending on how much your coach alone weighs.
IF your MPG calculations are based on computing them on a single refill, that explains why you seem to have better than most ďaverages ď. Unless you calculate the average over several fillings and at least 1,000 miles it isnít a realistic average.

Not trying to seem critical, just trying to offer my thinking on both subjects. Ed
edgray is online now   Reply With Quote
Old 05-23-2022, 08:15 AM   #7
Senior Member
Domo's Avatar
Join Date: Sep 2018
Location: Fort Myers, FL
Posts: 1,310
Generally, the best way to improve mileage is to check weight vs. tire pressure, make sure the air filter is clean, find the optimal power rpm for your motor and plan on going slowly up hills by downshifting to keep the motor near the ideal rpm.

Start slow, leave plenty of room to coast towards a gentle stop and enjoy the scenery.

We get (nearly) 8 mpg on a good day when fully loaded and towing our Jeep Cherokee. We drive at 63 with occasional excursions to 70 if downhill and little traffic. We get to drive in the slow lane going up mountains...
2008 Phaeton 36QSH, Safe-t-Plus, Quadra Bigfoot
2017 Jeep Cherokee Trailhawk w/ flat tow wiring mod.
Blue ox, BrakeMaster + BrakeAway, diode lights and charge.
Domo is offline   Reply With Quote
Old 05-23-2022, 08:57 AM   #8
Senior Member
computerguy's Avatar
Join Date: Jul 2010
Location: FT on the Road
Posts: 3,302
Yeah something doesn't sound right. Slower speeds should generally yield better MPG. Details matter too. Were you always using regular gas? Was there hills, wind on the tank with the lower MPG?
I track all gas mileage since I went full time in 2017:
Miles MPG
6263 6.4 2021
20899 6.3 Since FT in 2017

I am right at 22,000 lb GVWR and tow a Ford Focus at 3200 lbs. generally driving at 62MPH. I notice the biggest variance when I have a head wind or a cross wind. It can lower that by 2 MPG easily.
I don't make it much on here anymore so will not see your reply to my comment. Drop me a direct message and when I come back on I will see it.
computerguy is offline   Reply With Quote
Old 05-23-2022, 09:05 AM   #9
Senior Member
Sweetbriar's Avatar
Thor Owners Club
Ford Super Duty Owner
Join Date: Jul 2011
Posts: 3,647
Couple of things to help improve mileage.

1. Reduce coach and tow weight. Each spring I empty the coach and anything I can't recall using the prior year doesn't go back in. I usually only travel with maybe 5-10 gallons of potable water and empty waste tanks. Every little bit helps.

2. Keep the tire inflated to the maximum necessary for the weight of the coach OR to the pressures listed on the Ford Incomplete Vehicle Tag. Ford's pressures will give your tires the weight capacity to match the axle capacity.

3. Leave the toad at home unless you have definite plans to use it. I rarely take the toad along for weekend trips but longer trips with site seeing plans I bring it along for the ride.

4. SLOW DOWN. 2500 RPM should have you running down the road at 62-65 which is a good safe, fuel and time efficient speed. I can't recall the formula for air resistance changes with speed but it's substantial and the 100+ SqFt of frontal area of the brick we call a class A doesn't help much.

A good tool to help with your right foot is a Scan Gauge which you can set up to display both average and instant fuel mileage as determined by the ECU. Seeing an instant number of 2.2 MPG has a way of getting you to back off a bit.

If your speed reduction and mileage decrease was based on a single fill up you really need several to establish a true average number. Only takes a few gallons more or less as part of a fill up to give you a mile for two of change in the calculated MPG which is easy to do when filling a 70 gallon tank. A strong head wind, a few miles of stop and go traffic, generator usage,,, will effect the calculation. I have over 187 fill ups and my MPG has varies from a low of 4.7 (my one and only time to experience a summer Friday evening Washington DC traffic) to a high of 8.74 with my average holding around 7.2.
2006 Hurricane 31D built on a 2006 Ford F53
Sweetbriar is offline   Reply With Quote
Old 05-23-2022, 09:59 AM   #10
Senior Member
Join Date: Dec 2013
Location: Lake Havasu City, AZ & Plover, WI
Posts: 5,437
This is info from the Cat RV Performance Guide. It reflects my actual experience when checking mileage at different speeds.

A 34,000# motorhome will need 126 hp to overcome rolling resistance and wind resistance. That same coach will need 153 hp to travel 65 mph. Push it up to 70 mph and it will need 184 hp.

Every horsepower needs fuel. The higher the HP requirement, the higher the fuel consumption.

Edit: 70 is 16% faster than 60 so more miles are covered. However, 184 is 46% higher HP needed to do it.

Some might find this info useful.
2013 43 QGP Allegro Bus
2013 Avalanche
2000 AEV TJ
Crasher is offline   Reply With Quote
Old 05-23-2022, 05:36 PM   #11
Junior Member
Join Date: Sep 2011
Posts: 12
Well, I rechecked the weight of the Jeep. On the door it says 5500 lbs. Figure that I fill the gas tank, put my mobility Scooter in the back, add in the braking system, and the Blue Ox Towing Bar, that sounds like the weight is close.
The mileage was on two long trips. One from Denver to Niagra Falls, and the other to New Orleans. Both took 6 weeks.
I always start up slow from lights, try to stay away from heavy traffic ETC. I use the speed control on flat lands and not in the mountains.
RPM is around 2000 to 2200 and I use the overdrive.
I don't know if it has an after-market chip and don't know where to look for it either.
I have had it for 10 years
Before this we had a 32-foot Bounder with a 460-fuel injected with overdrive and a full Banks system. The best MPG was at 52 MPH. 2000 RPM and 12.5 MPG on flat land towing the Escort. I did get 15 once with a tail wind.
I have had motorhomes for over 30 years.
Wolf-S is offline   Reply With Quote
Old 05-23-2022, 05:49 PM   #12
Junior Member
Join Date: Sep 2011
Posts: 12
My tires are Iron Man they have a higher rating then Goodyear or ETC. 15 to 20 %. They last longer also.
Wolf-S is offline   Reply With Quote
Old 05-23-2022, 06:10 PM   #13
Junior Member
Join Date: Sep 2011
Posts: 12
I have also made a spare tire carrier for is a second spare tire that installs into the trailer hitch. Adds 2 feet to the hitch. It has a pully system to raise and lower the spare. Less than 30 Lbs. needed to operate.
I'm a Mechanical Engineer and a Master Welder. This helps.
Wolf-S is offline   Reply With Quote
Old 05-23-2022, 08:42 PM   #14
Senior Member
DRM901's Avatar
Tiffin Owners Club
Texas Boomers Club
Join Date: Feb 2018
Location: North Texas
Posts: 1,205
I suggest you minimize your tanks. Empty the gray & black before every trip. Only keep enough water for the day. Don't fill your fuel tank; only do 1/2.

There is a lot of weight on those fluids.
2014 Tiffin Allegro Bus 37AP
DRM901 is offline   Reply With Quote

damon, gas, mileage

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
Damon Intruder 2004 367, Dash lights Quit Wolf-S Class A Motorhome Discussions 3 04-11-2022 03:46 AM

» Featured Campgrounds

Reviews provided by

All times are GMT -6. The time now is 06:13 AM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2022, vBulletin Solutions, Inc.