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MPG Poll

Yahoo Message Number: 1797
I would like to get an idea of what fuel mileage othes are getting with their diesel coach.

I have a 2000 40ft CC Intrigue w/ISC 350 engine. Has approximately 30,000 mainly interstate miles at speeds of around 65 mph. My mileage has been around 6.5 mpg for the entire time I have owned the mh. How does this compare with your experience?

Thanks
Ray

Re: MPG Poll

Reply #1 –
Yahoo Message Number: 1798
1996 Beaver Patriot 33'; CAT 300; Allison 3060; weighs about 24,000. Recent 4,000 mile trip to AZ & CA towing 3,500# Toyota at 60 mph = 8.52 mpg for the trip.

Glen R. Fotré, Portland, OR

glen@...
1996 Beaver Patriot/Toyota 4x4 Pickup FMCA-F36478 Good Sam-ZC0494229 BAC

Re: MPG Poll

Reply #3 –
Yahoo Message Number: 1800
"I would like to get an idea of what fuel mileage othes are getting with their diesel coach."

1999 36' Intrigue 350isc 9.4 mpg at 62 mph.

Sincerely

George W Becker

gwb36@... 1999 Country Coach Intrigue #10700

Re: MPG Poll

Reply #4 –
Yahoo Message Number: 1801
Hi George,

First, I would like to caution you that the MPG reported by the Cummins ECM via Silverleaf products is optimistically high. The only real method is miles driven between fillups divided by gallons used.
On a 2000 Allure 32' with an ISC 330 hp upgraded to a 350: 8.05 mpg over 5 fillups and several thousand miles.
Fred Kovol

--- George Becker gwb36@...> wrote:

Quote
"I would like to get an idea of what fuel mileage > othes are getting

with their diesel coach."

> 1999 36' Intrigue 350isc 9.4 mpg at 62 mph.

Sincerely

George W Becker

gwb36@... > 1999 Country Coach Intrigue #10700 >
LAUNCH - Your Yahoo! Music Experience http://launch.yahoo.com

Re: MPG Poll

Reply #5 –
Yahoo Message Number: 1802
1998 40' Intrigue, 325 Cummins gets 10.6 mpg traveling @ approx 63 mph when not pulling. Pulling Jeep Liberty gets 8.2 mpg at same speed. Always checked as total gallons used over 3 to 4 tanks divided by total miles.

Joey

Re: MPG Poll

Reply #7 –
Yahoo Message Number: 1805
Ray, I had a 2000 Intrigue 40' galley slide with the ISC 350 engine and consistently averaged 7.5 mpg net of .5 gal/hr for the generator and .2 gal/hr for the hydronic furnace. This was at speeds around 65 mph. At 70 mph it dropped to 6.5 mpg.

So far I'm getting about the same on a 2003 Allure with the isl 370.

Walt Rothermel
2000 Allure30811

Re: MPG Poll

Reply #8 –
Yahoo Message Number: 1809
"First, I would like to caution you that the MPG reported by the Cummins ECM via Silverleaf products is optimistically high."
-----------------

I am well aware of this. I contacted Cummins after talking to the SilverLeaf guy at a rally and he said only Cummins could modify the fuel flow rate display. Cummins basically said "tough luck". My mpg from SilverLeaf is about 10% high.

I have kept a spreadsheet of all fills from about 20000-50000 miles. Before the fan speed modification kit installation I got 8.2 mpg for 2400 miles.
After the installation I get 9.4 mpg for 16682 miles. At a slightly faster speed, also. I did an admittedly cursory thermodynamic study and convinced myself the fan hp change is sufficient to explain the mpg improvement.

If you want to discuss this further, contact me offline.

Sincerely

George W Becker

gwb36@... 1999 Country Coach Intrigue #10700

Re: MPG Poll

Reply #9 –
Yahoo Message Number: 1813
Hi mpg guys, Silverleaf products is considering the ability to user correct the high mpg Cummins ECM readout. Also, Cummins will fix a bug in their software in October 2002 to correct data buss outputs for total miles and engine hours after fuel recalibration to increase engine hp (eg: 330 to 350 on ISC). When comparing mpg, it is important to mention total weight, number of tires, and what is being towed as some folks have done.
Fred Kovol

--- George Becker gwb36@...> wrote:

Quote
"First, I would like to caution you that the MPG > reported by the Cummins ECM via Silverleaf products > is

optimistically high."
-----------------

I am well aware of this. I contacted Cummins after > talking to the SilverLeaf

guy at a rally and he said only Cummins could modify > the fuel flow rate

display. Cummins basically said "tough luck". My mpg > from SilverLeaf is
about 10% high.

I have kept a spreadsheet of all fills from about > 20000-50000 miles. Before

the fan speed modification kit installation I got > 8.2 mpg for 2400 miles.

After the installation I get 9.4 mpg for 16682 > miles. At a slightly faster

speed, also. I did an admittedly cursory > thermodynamic study and convinced > myself the fan hp change is sufficient to explain > the mpg improvement.

If you want to discuss this further, contact me > offline.

Sincerely

George W Becker

gwb36@... > 1999 Country Coach Intrigue #10700 >
LAUNCH - Your Yahoo! Music Experience http://launch.yahoo.com

Re: MPG Poll

Reply #10 –
Yahoo Message Number: 1819
8.2 mpg with 2001 Intrigue towing Jeep GC and 18000 miles on the
coach. You should be getting more, I'd think....Jan McNeill Intrigue 11320

MPG Poll

Reply #11 –
Yahoo Message Number: 1821
2001 Intrigue 40' w/ISL tow Grand Cherokee, driving from 57 to 65 mph. Got 8.5 to 8.7 for first 3k miles then learned more about driving diesel and bumped it up over 9. Total mpg for 13k miles is now at 9.1.

Earlier Fred wrote that mpg using Silverleaf is "overly optimistic".
I disagree. If one uses total gallons used between fills that would be very misleading. I run generator for air conditioning and use our diesel fired furnace for heat when parked. The Silverleaf uses only fuel passing to engine for measurement which is much more accurate.

Re: MPG Poll

Reply #12 –
Yahoo Message Number: 1822
Just as a point of reference or two, the president of Silverleaf products has stated that the Cummins ECM outputs optimistically high mpg data; 2nd, I didn't use my generator or anything else that uses diesel fuel on the last 3000 mile trip and my mileage was lower than reported by the Cummins ECM data which the Sivlerleaf is connected to.

That is why Silverleaf is considering a user input to fine tune its display of mpg. It is true that miles driven between fillups divided by fuel used is only an accurate number for road mpg if no other appliances that use diesel are used.
Fred Kovol

--- rvboomers rusco@...> wrote:

Quote
2001 Intrigue 40' w/ISL tow Grand Cherokee, driving > from 57 to 65

mph. Got 8.5 to 8.7 for first 3k miles then learned > more about

driving diesel and bumped it up over 9. Total mpg > for 13k miles is
now at 9.1.

Earlier Fred wrote that mpg using Silverleaf is > "overly optimistic".

I disagree. If one uses total gallons used between > fills that would

be very misleading. I run generator for air > conditioning and use our

diesel fired furnace for heat when parked. The > Silverleaf uses only

fuel passing to engine for measurement which is much > more accurate.
LAUNCH - Your Yahoo! Music Experience http://launch.yahoo.com

Re: MPG Poll

Reply #14 –
Yahoo Message Number: 1825
Fred, can you expound on the hp upgrade. Are you saying that if we have an engine upgrade we will automatically get a software upgrade to correct mpg and engine hours? If so what change is being done to engine hours?

Re: MPG Poll

Reply #15 –
Yahoo Message Number: 1827
We have 26,000 miles on our 2001, 40 foot Magna and we get around 7.5 mpg on flat open roads at 63 mph. When our speed goes up our milage goes down. At 55mph we get 8.5 but we do not drive that slow. We have a 385hp cat.

Bill G.

Re: MPG Poll

Reply #16 –
Yahoo Message Number: 1829
Hi Joey,

When I had my ISC hp upped from 330 to 350 at a Cummins dealer, for some reason the odometer miles and engine time at reported on the ECM buss was set to zero but did increase with driving. At a later time, the Cummins dealer set the ECM values to the gauge readings but the ECM on the data buss that the Silverleaf products provide readouts for miles and engine time did not update to the gauge readings.
Contacting Cummins engineering, the engineer stated that this software bug (along if other improvements) would be fixed and available in October 2002 - at what cost I don't know.
Fred Kovol

--- joeycam joeyc@...> wrote:

Quote
Fred, can you expound on the hp upgrade. Are you > saying that if we

have an engine upgrade we will automatically get a > software upgrade

to correct mpg and engine hours? If so what change > is being done to
engine hours?

Re: MPG Poll

Reply #17 –
Yahoo Message Number: 1831
Hi, I too would like to know what you mean when you say you have learned more about driving diesel. Any information would be appreciated. Thanks, Dale

Re: MPG Poll

Reply #18 –
Yahoo Message Number: 1833
Quote from: "
Can you tell us more about "learning to drive diesels"?
I can not speak for "rvboomer", but I will share a valuable resource that I found. Go to your local Department of Motor Vehicle Driver Training Center. Pick up the learners manual for CDL licensing. The manuals are free. These manuals identify several critical areas that operators of large diesel rigs should know. I live in Pennsylvania.
In PA, if you own a rig in excess of 26,001 pounds GVWR, you are required to obtain a "Class B, Exempt" license. It is not a CDL, but you are required to do a road test and have knowledge about your rig. The area that I was questioned most was with air brakes. It is true, you operate a diesel powered vehicle differently than you do a gasoline powered vehicle. The CDL learners manual will help you a lot.

Dave G.
2000 Allure

Mechanicsburg, PA

Re: MPG Poll

Reply #20 –
Yahoo Message Number: 1853
In South Carolina RV's are exempt from the 26,000 pd. ceiling, no CDL required.

Bill G.

Re: MPG Poll

Reply #21 –
Yahoo Message Number: 1962
I'm on the road right now so catching up on e-mail might seem like "old news" so bare with me....
My old(er) '98 Intrigue 40' w/ 325 Cummins got 6.98 for 49,500 miles. I factored in gen hours (didn't have diesel heat) at .5 gal per hour. I do have a rather heavy foot and lots of those miles were on major highways at 65 to 70 MPH.
In my '02 Intrigue 40' SD (towing a Jeep Cherokee) I'm getting 8.04 MPG after 6,300 using gen hours at .5 and hydronic heat at .3 gph. I don't even look at the Silverleaf fuel usage. I think my driving habits have improved a little and keep working at it.
I'm thinking about the fuel option from Silverleaf.... anyone have experience with it?
By the way... my record keeping is VERY accurate by using a program from ANALYTICAL SERVICES called ROLLING STOCK. It tracks fuel, maintenance, repairs, tires, etc. I only mention it because it works great for me... I'm not on their payroll. If interested check out their web site... http://www.sashasoft.com/
Dick May

2002 Intrigue, #11438
Member: CCI, FMCA
Dick May
2002 Intrigue, #11438, towing a
2014 Jeep Gr Cherokee ecoDiesel

MPG poll

Reply #23 –
Yahoo Message Number: 1808
Our Silverleaf has 8.7 MPG. We have a 98 Intrigue 40ft 350 ISC engine. We pull Jeep Cherokee. When we have divided we get about the same.

Linda

MPG

Reply #24 –
Yahoo Message Number: 1870
I've been tracking my fuel consumption since I purchased my 2000 40ft Allure, "LaPine" Oct 2000. It has a 330 Cummins. Weight is just under 33,000 with full fuel, water and LP plus I tow a Saturn L300. Normally drive 60-65 on freeways. We are full time and have been through the desert and up and down the mountains including Hwy. 101 from Newport, OR to Ocean City, WA. Although we try to stay a week at each location, many are shorter and some are longer. Currently have 12,450 miles of which about 3,100 were from delivery and not included in my calculations (distance/gallons). I track between fillups and overall average. Overall average is 7.6 mpg.
PS: Before anyone tells me I'm over weight on the 2000 Allure (32,200), my unit is an end of year model and has a heavier rear axle and I don't normally travel with full water or full waste tanks.

Dale & Rita (heinsdl@...)
2000 Allure 40' LaPine
# 30579

MPG

Reply #25 –
Yahoo Message Number: 26000
I have the 400 ISL engine-

Question- Is there a sweet spot for RPM that gives the best MPG? I don't have Silerleaf- would Silverleaf tell me that?
Also I've never change the air filter in engine- I'm the original owner with 50,000 miles- I've done the reset on the filter gauge- It pull's up the yellow tab in the clear cyclinder slightly- Also pulled the

hose off and checked for suction- with engine running- Suction seemed good-

Thanks for any help-

Stan vander ploeg
#11556 Intrigue 2003

Re: MPG

Reply #26 –
Yahoo Message Number: 26001
As slow as it may seem, we found that 55 gave us the best MPG. We have the 400 ISL as well.

Sue

Allure 31254

Re: MPG

Reply #27 –
Yahoo Message Number: 26002
We discovered the same, that 55 MPH is the sweet spot for us too.
55 to 65 the MPG goes down from about 9 to 7.
Driving at 55 also has another good side..
It is much more relaxing. It helps us just sit back and enjoy the trip.

Russ and Jean
05 Intrigue
11883

Re: MPG

Reply #28 –
Yahoo Message Number: 26004
The majority of Cummins ISL engines operate best "around" 1600 rpm - most rigs are geared to run at 55 mph at 1600 rpm. Peak torgue on your engine is at 1250 rpm so that gives you a good operating range between shifts. A number of tests were run within the trucking industry that suggest that your miles per gallon will decrease 1/10 of a mpg for each mph over 55 you drive ie. if you drive 65 mph avg. you will see approx. 1 mile per gallon less in overall mpg. These test were run back in the early 1980's and I have not heard of any tests run since that time that indicate anything different.

Naturally a number of things have an impact on your overall performance including how you drive, idle time, dirty air filter, oil change intervals, type of oil used, tires and tire pressure along with weight of the coach and if you are towing anything behind you. I would change your air filter ASAP if it is org. equipment with 50,000 miles on it regardless of the filter minder reading. It is not that expensive to replace and is far cheaper than an engine overhaul. Dirt is your engines biggest enemy. New, clean air, oil and fuel filters are your engines best friends!!

I have the ISL 370 hp which is in the same family of engine (different turbo) - I get my best mpg at 55 (as high as 9.1 mpg) but I find I generally drive around 58 to 60 and normally will see 8.3 to 8.7 mpg. Since we dry camp alot we use the generator regularly (and the Hurricane Heater) both of these bring my overall avg. mpg down. I believe 7.5 to 7.9 overall would be a fair number tp expect if you use your generator and heater on a regular basis.

My Silverleaf shows rolling mpg but does not show overall trip mpg.

Hope some of this helps you.

M. Peterson

03 Allure #30916

Quote from: stanley20002152
I have the 400 ISL engine-

Question- Is there a sweet spot for RPM that gives the best MPG? I > don't have Silerleaf- would Silverleaf tell me that? >

Also I've never change the air filter in engine- I'm the original

owner

Quote
with 50,000 miles- I've done the reset on the filter gauge- It

pull's

Quote
up the yellow tab in the clear cyclinder slightly- Also pulled > the

hose off and checked for suction- with engine running- Suction

seemed

Re: MPG

Reply #29 –
Yahoo Message Number: 26006
There is a interesting tech. report published by CAT. but applicable to all engines relative RPM (speed) and fuel economy, as related to aerodynamics of most coaches. Everyone is right 55-60 speed for greatest mileage. See CAT. for report.

Re: MPG

Reply #30 –
Yahoo Message Number: 26017
AT home comming during a Cummins seminar we were told you must change the filters when dirty or every two years. The adhesive that holds the filterpleats in place will fail and if it does and (the filter is dated) the repairs will be all yours. And I understand that can be a very very expensive proposition when all that gunk gets in the turbo and in into the cylinder heads. TWI 11731 2004 Intrigue w2ith ISL

Re: MPG

Reply #32 –
Yahoo Message Number: 26031
Mike,

Interesting paper that's a keeper. It will be worth reading.

Thanks,

Jim Hughes

2000 Allure #30511

Quote from: Mike Cebula\[br\
]
Cummins has a white paper on MPG. It is aimed primarily at the
trucking industry, but has good info in it. I learn a bit more
each time I go through it.
http://www.cummins.com/na/pdf/en/products/truck/MPG_Secrets_Whitepape .pdf

Quote
Mike

'95 Magna 5266

James Spivey wrote:
>
>

> There is a interesting tech. report published by CAT. but
applicable to

Re: MPG

Reply #33 –
Yahoo Message Number: 26039
50,000 miles on the original air filter. You must be kidding. That engine has to be in labor just to keep running. If you have black soot every time you accelerate your starving for fresh air.
I've read your message 3 times just to be sure.
You don't even know if you have an air filter in the filter can. Maybe that's why its still running.
Absolutely shocked in KC
AL

00 affinity #5851