mileage

[RJ]

My advice for keeping your spirits up at the end of a trip:

Budget for 5mpg, that way, you'll have change left over!

I'll jump in with another guideline:

Using whatever means you have of tracking the mileage (speedometer's odometer, hubometer, GPS, computer, etc.), FILL the tank when you've driven 500 miles since the last fill-up. 


Exception:

If you have a diesel genset that share's the coach's fuel tank, and not a separate one of it's own.  In that case. . . well, perhaps it's time to rethink the genset's fuel tank situation if you want to avoid embarrassment.   

FWIW & HTH. . .

[belfert]

I usually go 800 to 900 miles per tank on a long trip, but I also get 8 MPG.  With a 150 gallon tank that leaves around 1/4 tank left when I fill.  My fuel gauge is broken, but I check on remaining fuel when stopping to change drivers.

My fuel tank is a long rectangular tank that runs from side to side in the bus.  There is a large door on each end of the tank.  the filler neck is only about four inches long and I can see the fuel level in the tank.  I always fill to the same point every time.  I use a handheld GPS to determine miles driven.  I think my MPG is reasonably accurate.

[Stan]

Bus Warrior is right on target. All the variables make it impossible to have an accurate MPG. It has to be calculated over thousands of miles without ever running a genset or a heating system of the engine tank, over different types of terrain, with some accurate way of measuring distance and total volume of fuel used.

Just read through all the threads on MPG and you find two types. Some brag about their high mileage and some complain about their low mileage but all have it figured out to a decimal point.

Run border to border on IH 15 with your foot in it and you will be lucky to get 5 MPG. Run on the South end of IH 95 at 55 MPH (with a tail wind) and you will do considerably better.

[Songman]

I suspect Don gets good mileage because he is intimately familiar with Detroit 2 strokes and he did some work on his motor.  His idea of a tuneup is a little different than most as he replaced injectors and the turbo during his tuneup. 

The great thing about this idea is that Don is right here among us and can help us all achieve what he does. While it doesn't seem fiscally feasible to me to go through all the trouble and expense of swapping in a 4-stroke just to hope I get a small MPG improvement, spending a small amount on injectors and turbo would make a lot of sense. From what I have learned from Don, in most cases you don't have to replace the entire turbo but just parts of it. Of course, depending on what you start with changing the entire turbo may be the only way.

As for variations, the one Russ stated is the easiest and unless you want to talk thousandths is accurate enough to give you an idea. Fill it up, drive it, fill it up again and do the math. True, you might not fill it to the exact same point but you will be able to tell the difference between 5 and 9.. or even 9 and 9.5. No reason to make all this rocket science. Don's calculations come from miles driven/gallons used.. and luckily for him, his Country Coach is equipped with a computer that backs up his findings.

And for those of you running on 15 with your foot in it getting 5 MPG - Slow down and enjoy the ride.. and the improved fuel economy.

[JohnEd]

Songman...and Don,

Do you have experience with someone that had a tired and low performing 6/8V92 or 71 that had the injectors and turbo changed out as a routine maint action?  What was the MPG increase?  Can't I tell if my turbo is up to snuff with a boost gauge?  Won't a check of the ex manifold temps for each cylinder tell me if my injectors are "matched"?  In short, do I need to do this as a routine PM?  And I would do that if need be....like an airplane engine part whose failure would simply ruin your morning.

That is great advice about not overcomplicating the thing, Songman.

Thanks,

John

[makemineatwostroke]

Guys, one thing  about mileage on a engine is larger the horse the more hay it eats, prime example Newell's 625 hp C15 Cat 4.5 to 5 mpg on a modern 4 stroke

[Len Silva]

I really think that all it takes is to keep the weight down and keep your foot out of it.  If you are going to drive a 50,000# conversion, it's going to cost a lot more than a 30,000# unit.

I believe that if you took two identical coaches with dramatically different engines (say a 6V-71 and a 500HP Series 60) and drove them side by side, accelerating at exactly the same pace, that the mileage would be very close.  The problem is that when we have 500HP, we tend to use it. Pretty hard not to.

The person who paid $1,448,900  for the Newell doesn't care if it gets 5 MPG or 2.