Community Forums

Sky_Boss · 07-11-2013, 12:50 PM

400 HP Cummins and the numbers include fuel burn of the generator.

From my GAS CUBBY APP

January 11-July 11, 2013 which includes a lot of cold starts, short trips, and instructional driving.

Aver MPG 6.18,
Max was 7.63,
Minimum was 4.27
Total Cost $2394.66
Total Miles 3904
Total Gals 631.27
Total fill ups 13
Cost per mile $.61
Miles per $ 1.63

However, the last 3 months with long trips and a toad along with generator usage while driving to run AC for the most of the miles

Aver MPG 6.49,
Max was 7.63,
Minimum was 5.90
Total Cost $1556.70
Total Miles 2675
Total Gals 412.24
Total fill ups 7
Cost per mile $.58
Miles per $ 1.72

Finally, the last 30 days with really long trips and warmer temps. Nearly all with genny running the AC units along with 2 boondocking nights. Only about 900 with toad.

Aver MPG 6.79,
Max was 7.63,
Minimum was 6.38
Total Cost $744.20
Total Miles 1373
Total Gals 202.27
Total fill ups 3
Cost per mile $.54
Miles per $ 1.84

WILDEBILL308 · 07-11-2013, 02:53 PM

I am on the road currently spending the night in Louisa Va. I installed a Banks Economind diesel tuner and IQ. One of the features on the IQ is you can calibrate your speed using GPS. I found I was running 5.7% faster than what my speedometer was showing. I also checked using the mile markers for 5 miles at 60 mph. The gps speed and mile markers are close enough. I will check my mileage and poste it latter.
Bill

Cooperhawk · 07-11-2013, 02:58 PM

This maybe unfair but our old Airstream Turbo Diesel has gotten as high as 16 mpg on trips. Okay, it only weighs 16000 lbs which is probably a factor. We've retired it now but it still gets better than 10 mpg just locally.

Weight really does matter.

Razzman · 07-11-2013, 04:38 PM

I have no clue what my mileage is, nor do I care to know. It's just like my boat, I accept that it is what it is. If I knew what it was then I'd just dwell on it, and that takes the fun out of it IMO.

CampDaven · 07-11-2013, 05:02 PM

So, I just gotta wonder....

With all the variations of rigs, what is the point of this thread?

Just wondering....

WILDEBILL308 · 07-11-2013, 06:01 PM

Quote:

Originally Posted by CampDaven

So, I just gotta wonder....

With all the variations of rigs, what is the point of this thread?

Just wondering....

That is the point.
Bill

Geneandea · 07-11-2013, 06:46 PM

I get 10 to 10.75 with a 1999 HR 250 HP Cummins 38' 38000# with a toad running 58-60 mph.

WILDEBILL308 · 07-11-2013, 07:30 PM

I am on the road currently spending the night in Louisa Va. I installed a Banks Economind diesel tuner and IQ. One of the features on the IQ is you can calibrate your speed using GPS. I found I was running 5.7% faster than what my speedometer was showing. I also checked using the mile markers for 5 miles at 60 mph. The gps speed and mile markers are close enough. I checked my mileage and on one leg it went from 8.6364 to 9.1286 after correcting the mileage. I wonder how accurate the different speedometers out there are are and how the differences affect the reported mileage.

Bill

Sky_Boss · 07-12-2013, 05:54 AM

Quote:

Originally Posted by CampDaven

So, I just gotta wonder....

With all the variations of rigs, what is the point of this thread?

Just wondering....

ON MY SOAP BOX

Ya know...different strokes for different folks. If one doesn't find value in any particular thread, then why say anything at all? Personally, I find questioning the questions of others pointless because it just sounds...well...pointless.

Each of us has questions that are particular to our desire for information. Sometimes the answers to what others might consider are pointless questions are as instructive to to OP in their quest be become informed. Early on I certainly asked what some might have considered as pointless questions. It was through thoughtful answers that I realized that in some cases the answers lead me to the conclusion that it just didn't matter. I, for one, tend to like to pick the fly crap out of the pepper only to find the answer didn't have a major impact on the big picture. Still, I had to explore those questions to ensure I wasn't missing something.

As one that is rather anal-retentive

, it is how I explore concepts. YES...it is a curse.

OFF MY SOAP BOX

flaggship1 · 07-12-2013, 08:14 AM

Don - Dave certainly doesn't need me to defend him but I think the point to his "pointlessness" is that we all look forward to your spreadsheet analysis of the thread of mileage by rig age, condition, type, weight, circumstance, modification, toad or no toad, tires, speed and distance analysis. I think a new emote may be needed - the tongue in cheek.

Correlating these numbers into anything useful would be pretty difficult. AND no - there is no usefulness requirement for threads. Many like this one (and one I have running) are more for fun and the enjoyment of chatting about or beloved beasts and lifestyle.

Have fun. Be happy. You're dream is just around the corner brother. Work on that AR curse. ATC is already at your side and will soon be in the review mirror. Me and Annie in our little 325 HP ISB that gets between 8.6 and 9.6 is right behind ya. And we really look forward to circling the wagons. Thanks for loaning me your soapbox.

Your friends, Steve and Annie

hogdriver · 07-12-2013, 08:24 AM

My gut feeling is the MPG figures are of course affected by; terrain, weight of RV and toad, wind and driving style but I also believe the moderately older RV's get better mileage than the newer ones. I know engines break in and get better with some age, but also any of the 2010s and up with 500-1000 lbs of emissions gear and the work they place on the motor gotta affect mileage. As I recall 50-60's cars got pretty good mileage until they got heavy and the emissions gear put on. Now auto engines are so sophisticated to get good mileage you have to be a software engineer to work on them and diesels are doing the same thing!

Sky_Boss · 07-12-2013, 08:30 AM

Quote:

Originally Posted by WILDEBILL308

I am on the road currently spending the night in Louisa Va. I installed a Banks Economind diesel tuner and IQ. One of the features on the IQ is you can calibrate your speed using GPS. I found I was running 5.7% faster than what my speedometer was showing. I also checked using the mile markers for 5 miles at 60 mph. The gps speed and mile markers are close enough. I checked my mileage and on one leg it went from 8.6364 to 9.1286 after correcting the mileage. I wonder how accurate the different speedometers out there are are and how the differences affect the reported mileage.

Bill

OH...a detail oriented person like me. LOL My MH isn't terrible and perhaps it shows about 1 MPH less than my GPS when I am running 62 MPH per my GPS. doing the math it means I am actually getting .0162 more MPG than I thought.

However, your case is interesting. Consider that you, too, also targeted 62 MPH (seems like a popular target speed) for fuel efficiency. First, the speedo was not showing you going as fast as you actually were so it would seem to me that it would also show less MPG. Second, on top of that, you were actually going about 65.5 MPH with the added aerodynamic drag which would also push your MPG down further. Finally, you are running a tab bit higher RPM which has a tad bit of an effect on MPG.

Theoretically, that means even after you fix your MPG calculations to your real miles driven, you should see a minor improvement in MPG because you will be going slower. Per the "rule of thumb" (See slide 19 in FMCA presentation FMCA Presentation - Cummins Engines) that 3 MPH costs you about .3 to .4 MPG. That is even before you add the Banks tuner to the equation.

Sorry...got carried away with the math. LOL