Miles Per Gallon

[Pa Miller]

The 5.9b 12valve with 7100 fuel pump and 3060 Alison is a awesome combination to me and the millage per tank always surprises me too!!!

[greystroke]

Originally Posted by Pa Miller

The 5.9b 12valve with 7100 fuel pump and 3060 Alison is a awesome combination to me and the millage per tank always surprises me too!!!

I have the first electronic version of the 24 valve ISB 5.9L and my economy varies 9-12. Cummins computer reads out 10.1 for 100000.
MD3060 tranny. Believe it . It is true. My toad is 4000.

[Pa Miller]

Originally Posted by greystroke

I have the first electronic version of the 24 valve ISB 5.9L and my economy varies 9-12. Cummins computer reads out 10.1 for 100000.
MD3060 tranny. Believe it . It is true. My toad is 4000.

Thanks ... it's making a believer outa me... We love ours they should still be making them !!

[mel s]

Originally Posted by Pa Miller

I can get 12 all day pulling my toad at 65 ....

Originally Posted by Pa Miller

The 5.9b 12valve with 7100 fuel pump and 3060 Alison is a awesome combination to me and the millage per tank always surprises me too!!!

Pa Miller
Good for you!
As you have seen 12MPG IS "unusual"...(Enjoy it).
Mel
'96 Safari, 8.5 MPG towing a Saturn ION

[Pa Miller]

Originally Posted by mel s

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Pa Miller
Good for you!
As you have seen 12MPG IS "unusual"...(Enjoy it).
Mel
'96 Safari, 8.5 MPG towing a Saturn ION

Thanks Mel

[Cat320]

12 mpg is great. You have a choice, small lighter coach and good mpg, or larger heavier coach with bad mpg.

[1ciderdog]

I had a 28 foot 1991 Safari Trek on an Isuzu chassis powered by a four cylinder diesel. Got real good mileage but was slow on hills and limited on towing capacity. Kind of wish I still had it.

[Piker]

Originally Posted by Pa Miller

The 5.9b 12valve with 7100 fuel pump and 3060 Alison is a awesome combination to me and the millage per tank always surprises me too!!!

Agreed.

I'm one of those spreadsheet geeks... so below is the data from our last trip.

I used a constant for gallons per hour of generator fuel in order to try and separate the fuel usage of the cummins from the onan... The generator manual says .9gph is the fuel usage at full load. There is nothing in the manual that says what no load usage is, but I have read it's probably around .3gph. It's a 7500kw diesel... it's not the inverter type that regulates rpm based on load... It runs 1800 rpm all the time. I settled on an estimate of .5gph to run the generator.

As you can see... over the course of our 7500 mile trip, the cummins averaged 11.3mpg. FYI... For every .1gph change you make up or down on the generator, you get a .2mpg change up or down (respectively) on the cummins.

For further reference... our rig is 35' long and weighs 19,000 empty (well... with me in it). We do not pull a toad.

You can see how it's impossible to check mileage on a single tank. The trip mileage ranges from 9.4 to 13.5... The reason is because on a large fuel tank (ours is only 90 gallons) you can easily be off perhaps 10 gallons from one fill up to the next depending on how level you are sitting at the station. You have to take a running average... and if you can... make the starting and ending fill ups at the same pump.

-cheers

[Pa Miller]

Wow Piker !! lot of good info there I like stats too..... I have a place I fill up every time we return from a little over 800 miles my tank suppose to hold 130 gals I keep it full .. What engine and tran are you running !!

[Pa Miller]

Originally Posted by Cat320

12 mpg is great. You have a choice, small lighter coach and good mpg, or larger heavier coach with bad mpg.

True Cat , I do most all the work on mine..... got to be ready to roll when the boss says so... lol I guess it's all about what you need or want in a coach .. We have adapted to our small one perrty good for just the two of us.. Hope fuel prices stay down for about 25 years lol !!! Planning on putting a lot more miles on this one !

[Piker]

Originally Posted by Pa Miller

Wow Piker !! lot of good info there I like stats too..... I have a place I fill up every time we return from a little over 800 miles my tank suppose to hold 130 gals I keep it full .. What engine and tran are you running !!

It's the old 12valve MD3060 combo. I've tinkered with the engine a bit - slight adjustment to the AFC... machined the fuel plate to mimick a #10 TST... adjusted the boost up to 32 lbs... and made the exhaust "free flowing." Just based on TST's charts, I'm guessing its around 300hp now. Give or take. Runs really good... the #10 is tuned a little hot for a 10 ton rig, so I do have to watch the EGT gage. To make sure I don't cook anything, I wired a buzzer up to the EGT gage that goes off when it starts to get too hot. Works slick. I saw no noticeable drop in fuel economy when I made the changes... but to be fair, I didn't have a spreadsheet before the changes.

In my mind, I kind of like the smaller class A's for maneuverability. I can go pretty much wherever I want and don't feel the need for a toad. Although maybe someday I'll pull a toad just for fun... but that's down the road a ways...

-cheers

[Pa Miller]

Originally Posted by Piker

It's the old 12valve MD3060 combo. I've tinkered with the engine a bit - slight adjustment to the AFC... machined the fuel plate to mimick a #10 TST... adjusted the boost up to 32 lbs... and made the exhaust "free flowing." Just based on TST's charts, I'm guessing its around 300hp now. Give or take. Runs really good... the #10 is tuned a little hot for a 10 ton rig, so I do have to watch the EGT gage. To make sure I don't cook anything, I wired a buzzer up to the EGT gage that goes off when it starts to get too hot. Works slick. I saw no noticeable drop in fuel economy when I made the changes... but to be fair, I didn't have a spreadsheet before the changes.

In my mind, I kind of like the smaller class A's for maneuverability. I can go pretty much wherever I want and don't feel the need for a toad. Although maybe someday I'll pull a toad just for fun... but that's down the road a ways...

-cheers

Same combo as mine , if you ever do pull a toad ours pulls the HHR like's not even there ... Have a great day !

[mel s]

Originally Posted by Piker

The trip mileage ranges from 9.4 to 13.5...

Piker


The overall MPG of my coach is just over 8.5, (actually 8.525 MPG).

That overall MPG was calculated by dividing the total number of miles I've driven my coach, (148,427), by the number of gallons of diesel fuel I purchased (17,411).

How many miles per gallon does your coach get overall?

Mel
'96 Safari

[Piker]

Originally Posted by mel s

Piker


The overall MPG of my coach is just over 8.5, (actually 8.525 MPG).

That overall MPG was calculated by dividing the total number of miles I've driven my coach, (148,427), by the number of gallons of diesel fuel I purchased (17,411).

How many miles per gallon does your coach get overall?

Mel
'96 Safari

When I say the "trip mileage" I'm referring to just the miles between each fill up... as if using the "trip" meter on your odometer. It varies because of the amount of fuel you can actually get into the tank at each fill up.

The "Engine Mile Per Gallon Running Average" column recalculates the average fuel economy at each fill up. After 7461 miles, we measured 660.1 gallons of fuel through the Cummins... the average then is 11.3 for the Cummins.

There was an additional 61.3 gallons of diesel that is estimated to have run through the generator over the 122.6 hours that we used it on this particular cross country venture... you can see that the column at the end is labeled "overall mpg running average..." this recalculates (at each fill up) the average miles per gallon and includes whatever fuel the generator used. This turned out to be 10.3 on the spreadsheet.

I guess I could have labeled the columns a little more descriptively for everyone...

-cheers