fuel mileage

[jelmore]

My mileage was highway miles only other than rest stops and a fuel stop. I know it drops dramatically with city driving and idling.

[phorner]

We put on just over 7,000 miles last trip out and averaged 7.7 MPG over the trip. It's my understanding that the Pro Driver calculates mileage based on the fuel flow thru the injectors and therefore the use of the generator or Webasto would not impact these numbers.

I usually drive just under 65 mph and tow a Jeep Liberty. Speed and weight are the only things that I have much control over and I try to use both to my advantage whenever possible.

My original goal was 6.5 MPG as a good number to shoot for, so I'm real pleased, and frankly surprised, with the 7.7

[BrianE]

The Pro-Driver only records fuel going through the engine. Generator usage can have a significant effect on overall fuel burn as it uses about a gallon an hour. The only way to accurately calculate total fuel usage per mile including generator and Webasto use is to divide miles driven between fillups by gallons added. Don't miss the current "Pyrometer Gauge" thread which has additional good info on fuel usage.

Incidentally, idling the engine for long periods of time is not necessary. Aside from an idle period during initial startup for a days drive, extended idling is a waste of fuel. Depending on the outside air temperature and the integrity of your air system this period should probably average no more than 10 minutes or so.

Hillndale: Take a look at the signature most of us add to the bottom of our posts. Knowing the year, converter, and type of toad assists everyone in answering your questions. You can easily add a signature by using the "Quick Links" drop-down menu at the top of the page.

[Loc]

It would help to know what year of coach you are driving. Mileage will depend on how much pollution control equipment is on the engine. In our 2002 XLII, I average about 6.8 to 6.9 mpg over a variety of driving terrain pulling a 04 Tahoe. I generally drive just below the speed limit (68 in a 70). At 3.6 mpg something is wrong even if it is a newer model. Are you checking based on the display on the dash or the old fashioned way of measuring miles traveled versus gallons used. Remember that the generator and Aquahot will result in lower percieved mileage based on the old fashion method. If you are using the dash display reset the display and try it again.

[Petervs]

Hillndale, the idle time does not affect the prodriver mpg readout, it does affect the fuel used readout.

At idle, you are burning maybe 1 or 1.5 gallons per hour, at high idle maybe 3. How many hours was ir idling and why?

Jon, you can program your DDEC to correct the miles driven. Using a code reader there is an input page where ypu tell the DDEC how many tire revolutions is a mile based on the diameter of your Chinese tires, it alo needs to know the rear axle ratio, etc. But you can get it exactly correct.

[hillndale]

It would help to know what year of coach you are driving. Mileage will depend on how much pollution control equipment is on the engine. In our 2002 XLII, I average about 6.8 to 6.9 mpg over a variety of driving terrain pulling a 04 Tahoe. I generally drive just below the speed limit (68 in a 70). At 3.6 mpg something is wrong even if it is a newer model. Are you checking based on the display on the dash or the old fashioned way of measuring miles traveled versus gallons used. Remember that the generator and Aquahot will result in lower percieved mileage based on the old fashion method. If you are using the dash display reset the display and try it again.

The coach is called an '07 by Featherlite but the actual chassis was built in Nov '05. This mileage is based on the Pro-Driver display. I did some calculations based on miles driven and came up with about 4.1mpg. That is with generator running at all times when driving and also running periodically while stored b/c we do not yet have electrical hook up for storage. I guess it still seems kind of low. I'm going to take it for a highway drive later with the display reset and see what we came up with.
Cany anyone think of any specific engine issues that could cause drastically decreased mileage if in fact the 3.6mpg's are correct?

[Kenneth Brewer]

We get about 5.2 including hills, altitude, running the gen while stopped for an hour or so at rest stops maybe 2 or 3 times a day, and running the OTR the entire time, generally. This is according to the DDEC. I run the speed limit, on cruise control, which is generally no less than 70, up to 80 out west, unless it was close to freezing and below, or if it is raining, or heavy interstate traffic. This figure includes the entire trip result (the same over about 4 trips). Coach weight full of fuel and fresh water plus 2 people is right at 51000, with no axle overloaded. No tow.

[Jon Wehrenberg]

Jon, you can program your DDEC to correct the miles driven. Using a code reader there is an input page where ypu tell the DDEC how many tire revolutions is a mile based on the diameter of your Chinese tires, it alo needs to know the rear axle ratio, etc. But you can get it exactly correct.

I have no manual for the ProDriver and I have looked all over the Detroit site and on the internet for a book. Do you have one I can copy?

I would like to tweak it to more accurately reflect speed and distance.

[CAPT MOGUL & Sandy]

This is Sandy here. Since this is a learning forum---Why would someone run their generator continuously while driving on a trip? I'm being serious here to try and learn! I know sometimes we run the generator while driving to run one of the roof airs-- to cool the coach more, that is, if the dash air isn't enough. Just trying to learn more about the operation of the coaches.
Ed is in Music Camp with DANNS at this time or I would ask him.
Sandy

[Ray Davis]

Sandy,

It's hard to give you an absolutely correct answer. It's very common to drive down the road with generator running, to get additional air conditioning power.

However some coaches, like my Marathon, allow you to run two of the A/C's directly from the inverter while driving. That is one A/C per inverter circuit. If I want to have more, then I would need to run the generator while driving.

I do not know if your Royale is equipped in a similar fashion. If not, you would indeed run your generator while driving. It is certainly fine to do so.

Ray