Fuel Economy of your Motorhome

[ohhwell]

Originally Posted by Brockx

Fuel mileage calculation

Total miles driven divided by gallons purchased over several fill-ups is the only true method.

Modern computers are REALLY accurate and could be better than hand calculations unless you always fill up at the same pump in the same gas station.

At least they are in passenger vehicles, DPs may have a dealer MPG calibration to make buyers feel better about the purchase

[mel s]

Originally Posted by Brockx

Fuel mileage calculation
Total miles driven divided by gallons purchased over several fill-ups is the only true method.

Brockx
My 8 MPG average was calculated by dividing the number of miles I've driven since '01, (104,578), by the amount of diesel fuel I used since '01, (13,069 gal).
Mel
'96 Safari, 250hp, 3126 cat

[dsbear]

My 8.3 is hand calculated over 13000 miles

[chawkins99]

I've had my coach for nearly 2 years and put around 10,000 miles on it. I have the Cummins 330 ISC.

For the first few trips, I meticulously kept records of mileage and got numbers varying from 7mpg to 9.5mpg. Overall for about 2500 miles was about 8.3mpg.

Then I got a Scangauge and that reports similar numbers. Now I don't bother with the record-keeping. It is what it is.

I keep the Scangauge on instantaneous MPG and average MPG. Downhill makes me feel when I see it showing 9999 MPG. Uphill, not so much...

As someone else mentioned, in rolling hills, it's more economical to not use the cruise control as it will try hard to maintain the set speed. Without cruise, I don't mind if the speed drops 5-10mph as I know I'll pick it up again over the rise. Accelerate on the downhill to anticipate the uphill. BTW: I don't do this if it is impeding other traffic

My latest trip, filled up near home. Scangauge said I had 19 gallons left but could only squeeze 76 gallons in the 100gal tank.

[CampDaven]

Perspective:

I get about 8 mpg.
From where I was in AZ to this spot in PA is about 2300 miles.
At $3.85/gal I spent about $1107 on MH fuel coming back East. I spend about double that touring with the toad in a year.
If you get 9.5, you beat me by $175 on MH fuel. Over 2.5 weeks portal to portal, the delta looks pretty small.

Being beat by $350 round trip over a year looks even smaller.

BTW. Dont fill up in PA. It is another 40 cents or so; state taxes.

[WILDEBILL308]

Originally Posted by MSHappyCampers

Hi Mitch! We get about 8 MPG while towing a Honda Accord 4-down. I drive 60 MPH on Interstates and 4-lane roads, and 55 MPH on secondary roads, depending on conditions. I have the Cummins ISC350 engine.

Are you sure you are getting into 6th gear?
I am turning 1600 at 55 in 5th gear It won't shift up till 65 or about 1950 rpm then it's turning 1600 rpm in 6th. I am running around 1800 at 60 in 5th gear.
Bill

[CampDaven]

Originally Posted by WILDEBILL308

Are you sure you are getting into 6th gear?

I am turning 1600 at 55 in 5th gear It won't shift up till 65 or about 1950 rpm then it's turning 1600 rpm in 6th. I am running around 1800 at 60 in 5th gear.

Bill

The Windsor probably has a different gear ratio that goes with the 8.3 motor vs your 5.9.
I am in 6th gear at 57 with my Camelot with an 8.9.
Varies a lot and each has a diff sweet spot.

[Brockx]

Originally Posted by mel s

Brockx
My 8 MPG average was calculated by dividing the number of miles I've driven since '01, (104,578), by the amount of diesel fuel I used since '01, (13,069 gal).
Mel
'96 Safari, 250hp, 3126 cat

Originally Posted by dsbear

My 8.3 is hand calculated over 13000 miles

Two honest men, brings a tear to my eye.

I had some GM cars in the late 90's that were really accurate, Ford and Chrysler computers really stink, and sadly my new KIA is 10% optimistic.

My current MH overall is 7.8 however; I have seen 6.5 to 12.5 on individuals, just depends what angle the MH is setting when you fill.

[Musikboy]

Originally Posted by MSHappyCampers

Hi Mitch! We get about 8 MPG while towing a Honda Accord 4-down. I drive 60 MPH on Interstates and 4-lane roads, and 55 MPH on secondary roads, depending on conditions. I have the Cummins ISC350 engine.

Hi Joe and Annette,

I started out with the expectation that 8 MPG would be just fine. When the Jeep arrives and adds about 4,000 lbs of weight, I will probably lose 1 MPG anyway. So we are in about the same position. We haven't yet hit the miserable heat of August so I don't know if we'll use the Gen for roof air. There's been several discussions around dash air using about the same fuel profile as the Gen itself. I certainly don't yet know how that will work for us.

My driving profile is more like yours, I am experimenting with 62 MPH (about 1700 rpm) since I've read several times that it's the sweet spot for good torque and economy. I haven't tried to use the mode button yet, I just read the manual today after someone here attached a pdf, so I will experiment with how that works next weekend when we are out again.

The best part is that I am calm and relaxed most of the time when driving the MH, which feels great. I don't know what hours of bumper to bumper traffic will do to my serenity, probably not fun but we do entertain ourselves with pod casts and stories so we are just enjoying our time together anyway.

Thanks for all your contributions here, I have learned so much from this group, it's really provided me with a jump start on this lifestyle.

[rufusfruge]

Hi Mitch, we have a 2014 Tuscany XTE 40 EX and I get 9.2 MPG pulling a jeep patriot. I'm hoping that I might push that up a bit after we get a few miles on it. I drive 62 mph and very light on the pedal. Use the cruise and the mode button whenever possible. My tire pressure is 120 psi before each trip and I watch it very closely. Good luck with the new Ray and enjoy the road. Rufus

[Musikboy]

Originally Posted by rufusfruge

Hi Mitch, we have a 2014 Tuscany XTE 40 EX and I get 9.2 MPG pulling a jeep patriot. I'm hoping that I might push that up a bit after we get a few miles on it. I drive 62 mph and very light on the pedal. Use the cruise and the mode button whenever possible. My tire pressure is 120 psi before each trip and I watch it very closely. Good luck with the new Ray and enjoy the road. Rufus

Rufus,

That's great news! gives me hope I can keep 9 mpg or better! I will have to check and watch my tire pressure, did you get those numbers by weighing on a truck scale? Are ALL your tires 120 psi or just your outer rears and front? What are your inner rear PSI measurements?

I hope you are having good luck with your 40 EX, we have just one small problem but otherwise problem free since leaving TN last Tuesday. Fingers crossed!

[SeattlePirat]

We have a 2004 Newmar Kountry Star with 300 HP Cummins ISB motor. After 50K we get approximately 11 mpg when we do not tow and 9.5 to 10 when we drag our 4400 lbs Chev Tracker.

Wind and hills are huge factors in mileage as is speed. There are times I wish we had a 330 hp Cat but not at the diesel pump.

[Musikboy]

Originally Posted by SeattlePirat

We have a 2004 Newmar Kountry Star with 300 HP Cummins ISB motor. After 50K we get approximately 11 mpg when we do not tow and 9.5 to 10 when we drag our 4400 lbs Chev Tracker.

Wind and hills are huge factors in mileage as is speed. There are times I wish we had a 330 hp Cat but not at the diesel pump.

Wow, that's great mileage! Just wondering, do you use DEF? Folks here are saying the DEF engines may be a little more efficient.

[CampDaven]

Originally Posted by Musikboy

Wow, that's great mileage! Just wondering, do you use DEF? Folks here are saying the DEF engines may be a little more efficient.

The 04 ISB is way before DEF and is a 5.9 in a much lighter coach.