Best economy

[mhenon]

I´ve been thinking about a spare fuel tank mounted in the truck bed. Also though about propane injection. I´m really not after big HP/torque gains with propane just a little extra push and hopefully an increase in MPG.

If there really is an increase in MPG using propane would I be better off, in the long run, to mount a propane tank in the bed or forget the propane all together and just add an extra fuel tank?

Given the price of propane over diesel fuel I would think the advantage would be with the propane. But..... with the extra fuel tank you could certainly wait between fuel ups to get the cheapest price... and maybe the MPG gain with the propane doesn´t add up to enough.

Anyway, if you were going to put another tank in the bed of your pick-up and the price of each installation was the same... which way would you go.

I´m really leaning towards propane at this time. Most of these systems can be set-up and controlled by the operator and I like the idea of a ¨mild¨propane injection while towing.

Any thoughts on this?



Thanks... . mike

 

[Groover]

Propane Injection

I can't imagine using the propane to help with fuel Mileage. It would be a great on demand assist when towing for extra power though.



Using propane would have to increase fuel mileage as it is adding btu's and also helps to burn the diesel more completely.



How much does the propane you are burning to increase your fuel mileage cost???



If you do not figure in that the propane tank needs to be refilled and what that costs at $3. 00 a gallon for propane then yes it improves mileage. Like if your brother in law was a propane distributor and filled your tank for free or something.



I doubt (my opinion) that it can be cost effective on mileage merit alone (i. e. propane used costs more than diesel fuel saved) and undoubtably somebody has tested this to see what the cost/ benifit is.



If you are looking for more power OK! Somebody would have to convince me that it is more economical than running straight #2 and then I still wouldn't believe it.



Flame away!

 

[Mundgyver]

Your better choice would be to just pop in a set of Bosh 275 injectors. They have seven small holes vs 5 big ones for the stock H. O. injectors that you now have. The fuel is atomized better during injection for a better burn. The results will be about a 25/30 hp gain and you should yield about 1 to 1. 5 mpg improvement. Drivealibility is very nice. The expense will be about 1/4 that of a propane system also. Thats my experience.

 

[dvaughan]

economy

Mhenon, how are you calculating your fuel mileage. If you are using your onboard computer, they are not accurate . I have a 2001 HO 6 speed with 355 gears and get 19. 5 to 21 mpg and that is Imperial Measurement . If you are getting 24 mpg(empty) and are doing it the old way by dividing your gallons into the miles driven then you are very lucky.

 

[Mundgyver]

I have gotten 24. 4 mpg only one time, but it has been awhile. My mileage is figured by topping the tank untill another drop will not go in. This is with rocking the truck to shake out the air in the tank also. I then divide into the mileage. This is the only method I use to caculate my fuel use, even though I have the onboard computer and the Roadrelay 4. Onboard computer is always off by 2 to 3 and the Roadrelay is off by 1 to 1. 5.



I have all my calculations since the day I bought the truck for 111,000 turns now.



Around Portland on the freeways I get between 19. 5 and 21. 5 in the summer and 18. 5 and 20. 5 in the winter. On trips over to Salmon, Idaho in the summer, I will average 22. 78 mpg per tank if I keep my speed between 60 and 65. If I am towing my trailer at 7,000 lbs in weight and at 65 mph in the summer I will get 18. 5 between Portland and Provo, Utah. These #'s are with the Comp in level 1 or turned off.



I run a 32 oz bottle of Power Service Additive every tank when I am on cross country trips. Around town, it is every other tank.



Worst mileage I have gotten is 16. 4 towing the trailer at speeds ranging from 75 to 85 through Southern, Idaho between Boise and Provo.



-Wally-

 

[rrausch]

I recommend the extra tank.



About 2 years ago I put an Aero Diamond-Plate 45 Gal tank in the bed of my truck. I plumbed and wired it up so that I can transfer fuel to the Main tank when needed by throwing a small switch. I added a green led on my gauge pod which lights up when the small transfer pump is working. The unit will Not pump if the key is not in the run position--(so I won't go off and forget the pump is on and flood the driveway. ) I also added a big Napa Fuel-filter/water-separator so most fuel gets filtered twice. I almost always save some money when I refill, and there have been times I have saved over $20 on a fill-up. But most of the time I only save 3-5 bucks. I can run 12-1600 miles with this set up if I have to without re-fueling, depending on if I am driving city or highway. I'm very glad I have it, and would really miss it if i had to do withoul. And in 2 years I have never been "dipped" by the Law. But then I don't run Red either!

 

[mhenon]

Thanks!!!

OK guys, thanks for the comments. I was really of the opinion that propane, properly injected, might increase the miles per gallon as it acts as a catalyst to give a better burn. Sounds like its just another power enhancement and won´t help with the MPG at all.

I´m sure the injectors will help but I can´t see making the change yet. Maybe when I burn out one of the original injectors I´ll consider going to the 275s or something.

As to the mileage the truck gets... . the >24 mpg is a good figure that I´ve verified many times. The bed cover actually gave me a solid 10% increase over the 22 mpg that I was seeing. That cover will pay for itself soon. I rarely see less than 20mpg at anytime unless towing.

Sooo... given that the rig is broke in and running great I realñy didn´t want to yank out injectors or modify any existing hardware. I want to install the TAG as soon as I get back to the states as the guys towing say it helps.

Thanks again for the advice on propane vs extra fuel tank. Think I´ll look for a spare fuel tank in the near future.



Mike

 

[Mundgyver]

mhenon,



Toss on some AirTabs on you cap and the trailer and put in a set of 275's and you should see another solid 3/4 to 1. 5 mpg.



Food for thought

 

[OnlyCummins]

There was a very long thread on the tdiclub website's "Non VW Group Diesels" forum titled "Best SUV" or something like that on which someone posted that his friend's Ford PS Excursion was getting ~27mpg with propane if you can believe that (I don't). I'm assuming it was being used as a mileage enhancer not power adder in that application. It does boost diesel burn -- from 80's percent to low 90's(?) percent -- from what I remember reading on the subject. Have also read of some diesels being completely converted to propane. In other words, propane only. The drivers of those trucks were supposedly complaining that their trucks no longer sounded like diesels.

 

[kbond]

Re: Thanks!!!

Originally posted by mhenon

OK guys, thanks for the comments. I was really of the opinion that propane, properly injected, might increase the miles per gallon as it acts as a catalyst to give a better burn. Sounds like its just another power enhancement and won´t help with the MPG at all.

I´m sure the injectors will help but I can´t see making the change yet. Maybe when I burn out one of the original injectors I´ll consider going to the 275s or something.

As to the mileage the truck gets... . the >24 mpg is a good figure that I´ve verified many times. The bed cover actually gave me a solid 10% increase over the 22 mpg that I was seeing. That cover will pay for itself soon. I rarely see less than 20mpg at anytime unless towing.

Sooo... given that the rig is broke in and running great I realñy didn´t want to yank out injectors or modify any existing hardware. I want to install the TAG as soon as I get back to the states as the guys towing say it helps.

Thanks again for the advice on propane vs extra fuel tank. Think I´ll look for a spare fuel tank in the near future.



Mike

I have a really hard time believing this milage. You must never take you truck above 60? Your profile doesn't say if you have a 2wd or 4wd. This would make a significant difference in my opinion for multiple reasons. Less drivetrain to drag, less weight, lower vehicle stance=less wind resistance etc... For my truck to get 24mpg, I think I would have to stay @ 55 with an egg under my go-pedal. What size tank do you have? If it is the 34 then you are telling us you see close to 800miles a tank? I would have to see to believe. Not mocking just envious if indeed true.

 

[mhenon]

Mileage

Kbond, You´ll just have to believe me on this one. The truck got about 21 to 22 mpg after break-in at say... 20k. I had a tongue (how do you spell that?) cover installed and the mileage went up to 24+ ... . constantly... not just a one time deal with a nice tail wind. This has been hand calculated on many long drives of over 1000 miles or more.

As to my speed... OK I´m a slow-poke. The mileage test where however done with the cruise control engage and a speed of 65mph every time. My towing mileage is calculated the same way but I usually drive just a tad bit slower while towing... . 62 or 63mph.

So thats it! Again that bed cover is a ¨huge¨help in the mileage department. Anytime you can get a 10% increase in efficiency go for it. The truck weight is 7550lbs with my wife (I could easily get 35mpg without the wife) and trailer is just over 10,000lbs. I´m right at max capacity when towing.

Thats the reason I was considering using propane instead of just adding a spare fuel tank. The extra weight of a tank (propane or fuel) would really put my total GVW at redline so I thought the added boast and fuel savings might be the way to go. Still mulling that over but don´t think the propane would be cost effective.

Anyway, I couldn´t be happier with this rig. I´ve wanted one since they put the Cummins in it and I´ll never own a gasser again. Thanks for all the replies.

Mike

 

[Vaughn MacKenzie]

Combined economy

Mike, when propane systems were discussed to death a couple years ago I kept asking "Is the net fuel economy greater with the combined cost of the fuels than with diesel alone?" The answers I got were generally "No. " As I recall when propane usage is computed into the MPG equation you came out about even or a little worse off than just burning #2.



OnlyCummins I can't see how a Cummins would run on pure propane. There is no way to control combustion & timing since it's injected into the intake airstream, not directly into the cylinders like diesel fuel. Engine speed, timing and power are all dictated by the injectors via the ECM.



Vaughn

 

[OnlyCummins]

Vaughn, Re: Propane Only: I don't pretend to know how it was done but if it's any help I believe I read it on one of the Ford diesel websites & I believe there was no ECM involved (purely mechanical?).



FWIW, there's a diesel-sounding but propane-smelling ice cream truck that makes deliveries in our neighborhood.

 

[Big Dawg]

These trucks can get great fuel mileage but you have to know how to drive them. Having the right truck helps too. Automatic 4x4's 3500's are not gonna fair as well as lighter trucks. I have recorded and hand calculated my mileage at every fuel stop I have made since I bought this truck. I usually average about 21 mpg in mixed hwy/city driving. I drive slow and coast as much as possible preferably in gear, which uses no fuel as long as you have a manual transmission and keep the rpm above idle. Oh I know... here it comes. WP and a few others will come out saying this is complete nonsense... Oh well... Remember these trucks are heavy and it takes more fuel to get them moving and up to speed than just to cruise at speed. As they say... Your mileage may vary...

 

[kbond]

Re: Mileage

Originally posted by mhenon

Kbond, You´ll just have to believe me on this one. The truck got about 21 to 22 mpg after break-in at say... 20k. I had a tongue (how do you spell that?) cover installed and the mileage went up to 24+ ... . constantly... not just a one time deal with a nice tail wind. This has been hand calculated on many long drives of over 1000 miles or more.

As to my speed... OK I´m a slow-poke. The mileage test where however done with the cruise control engage and a speed of 65mph every time. My towing mileage is calculated the same way but I usually drive just a tad bit slower while towing... . 62 or 63mph.

So thats it! Again that bed cover is a ¨huge¨help in the mileage department. Anytime you can get a 10% increase in efficiency go for it. The truck weight is 7550lbs with my wife (I could easily get 35mpg without the wife) and trailer is just over 10,000lbs. I´m right at max capacity when towing.

Thats the reason I was considering using propane instead of just adding a spare fuel tank. The extra weight of a tank (propane or fuel) would really put my total GVW at redline so I thought the added boast and fuel savings might be the way to go. Still mulling that over but don´t think the propane would be cost effective.

Anyway, I couldn´t be happier with this rig. I´ve wanted one since they put the Cummins in it and I´ll never own a gasser again. Thanks for all the replies.

Mike

Mike, I am guessing from the weight of the truck you have a 2wd? Also @ that speed I could see maybe 19+ mpg. Do you have a 34 gallon tank? If so, are you getting 680 plus a tank then?



Thanks,

Ken

 

[DOverton]

Hi Mike,

I seen this thread and had to jump on the band wagon! After installing a set of 370's and Dodgezilla turbo from City Diesel, My wife and I took a trip to MS. from Tuscaloosa, AL. With the cruise set at 60 MPH and the tailgate down we got 28 MPG. That seems to be the happy medium for it though. Any faster or slower the milage would start dropping. I also have the Gear Vendors that helps with slowing the RPM's quite a bit too. Before the Gear Vendors I got between 23 and 24 MPG. I'm very happy with my Cummins Diesel!!!

 

[mhenon]

Propane & mileage

Vaughn, yea thats kinda what I as after when posting this question and it sounds like it´s been discussed before. What were the best mileage reports using propane if you can remember. Somebody mentioned a Ford powerstroke getting 27+ mpg using propane. I would have to re-consider going to propane if I could get that. Thats better than a 10% increase which would be nice. And theres the added power while towing if it´s needed.

The problem is propane prices are about the same as diesel prices (around here anyway). In some places they´re way higher than diesel sooo?????

---------------------------------------------------------

Kbond, My truck does have the 34 gallon tank and it´s a 2wd. I edited my signature before my last post but it didn´t show up. I try to keep the tank at least half fuel so haven´t had a chance to check the total range on one fill-up. Once... I took it way past empty while towing and got over 420 miles at 12 mpg. If your truck is like mine you got a lot of miles left when it hits the empty mark.

-----------------------------------------------------------

DOverton, There is a thread on here somewhere about fuel efficiency with campers, bed covers, lowering the tailgate, etc. .

I forget what the increase is with lowering the tailgate but adding a bed-cover was worth something like 11% and thats about what I got. As I wanted a bed cover anyway it was a nice bonus.

 

[DKayser]

MPG

I have gotten 25 on only 2 occasions. From Boise to Twin Falls. The same trip twice. I have almost always gotten 20-22 on the highway. Wind seems to have the most effect on my mileage. If there is any significant amount of wind, head or cross, it really shoots down the numbers. Of course, this was not on winter fuel. That seems to cost me 2-3 mpg both town & highway. Howe`s in every tank of fuel,of course. I am tickled with the highway economy, but my town mileage sux. If I get over 15,it`s cause to celebrate. Usually get 14 or so. Taller tires than stock/235-85-16 may cause this. Don`t know. DK.

 

[OnlyCummins]

DKayser, if you haven't re-progammed your truck's computer(?) you aren't getting accurate mpg #'s. Rough estimate I use, assuming of course that the replacement tires aren't monster mudders, is to multiply the indicated mpg by the difference in tire diameter plus 1. E. g. , 10% diff & indicated mpg=25, then multiply 25mpgx1. 1=27. 5mpg.

 

[Groover]

To propane or not to propane?

Lets say your truck averages 15 mpg on #2. Being kind to the propane industry lets say propane increases mileage to 20mpg (that's 30% and what claims I have heard are more like 10%)



The propane systems recommend a 1:4 ratio of propane tank size to diesel tank size so I am assuming it is used in this ratio.



Lets use an 800 mile trip for example.



A) #2 only 800/15 = 53 gal diesel * $1. 50 it cost you $79. 50 to drive that 800 miles.



B) #2 and propane 800/20 = 40 gal diesel * $1. 50 it cost you $60. 00 to drive that 800 miles. OH! but wait we gotta fill up that propane tank too. 10 gal propane * $3. 00 gal is $30. 00 total cost for the 800 mile trip is now $90. 00



I am not against propane just pointing out that as a mileage increase add-on I don't see how it can work out more economical



my . 03