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wheres some good reading & info on propane injection???

4K views 21 replies 6 participants last post by  marcdeluca 
#1 ·
any info would be great.....thanks
 
#4 ·
thanks

What do you want to use it for, extra power once in a while or to cut cost per mile?
cut cost per mile for better fuel economy :D
 
#5 ·
Tough to do with propane these days. It has to be less than 2/3 the cost of diesel to save any money. $2 propane = $3 diesel.
 
#6 · (Edited)
While it is imperative to get the propane as cheaply as you can, it can be gotten anywhere from $1.50 to over $3.00 per gallon, so you have to shop around. If you establish yourself with a place, you can generally get a better deal. Why it varies in price, is well simply, because they can! Wholesale price is $.097 today. source is (www.thriftypropane.com)

It is also important not to use a ton of propane to acheive the ends.


Here is a sample taken from an OTR truck, but you get the idea.

10,000 Miles
5 Miles Per Gallon
$2.25 Per Gallon for Diesel
DIESEL COST
$4,500.00
COST PER MILE
$0.45

With propane and an additional
2 add. miles per gallon
10,000 miles
7 miles per gallon
$2.25 per gallon for diesel
$1.50 per gallon for propane
DIESEL COSTS
$3,214.29
PROPANE COSTS
$500.00
TOTAL FUEL COSTS
$3,714.29
COST PER MILE
$0.371
TOTAL DOLLAR SAVINGS
$785.71


 
#7 ·
While it is imperative to get the propane as cheaply as you can, it can be gotten anywhere from $1.50 to over $3.00 per gallon, so you have to shop around. If you establish yourself with a place, you can generally get a better deal. Why it varies in price, is well simply, because they can! Wholesale price is $.097 today. source is (www.thriftypropane.com)

It is also important not to use a ton of propane to acheive the ends.


Here is a sample taken from an OTR truck, but you get the idea.


10,000 Miles
5 Miles Per Gallon
$2.25 Per Gallon for Diesel
DIESEL COST
$4,500.00
COST PER MILE
$0.45



With propane and an additional

2 add. miles per gallon
10,000 miles
7 miles per gallon
$2.25 per gallon for diesel
$1.50 per gallon for propane
DIESEL COSTS
$3,214.29
PROPANE COSTS
$500.00
TOTAL FUEL COSTS
$3,714.29
COST PER MILE
$0.371
TOTAL DOLLAR SAVINGS
$785.71






Nice breakdown, that helps people understand the end savings, and how long it may take to recoup the cost of the system. Thanks for the info! :cool:
 
#8 ·
ok so now is a good time to mention i get propane for next to nothing :D
 
#9 ·
Here is my experience. A gallon of #2 is 140,000 btu. Divide that by 5 mpg, and you end up using 28,000 btu/mi. If the truck jumps to 7 mpg, it now uses 20,000 btu/mi. This means that the propane is providing 8,000 btu/mi, assuming that there is no magical efficiency gain. A gallon of propane is 91,000 btu. That divided by 8,000 is 11.4 mpg. At $500 for 10,000 miles at $1.50/gal, correlates to using 333 gal of propane. That is 30 mpg on propane. My real life results have been that the calculated mpg is very close to achieved mpg. At 11.4 mpg, the propane would actually be 10,000 miles/11.4 mpg = 877 gal at $1.50 = $1315 for LP. That plus the $3214 = $4529. No cost savings. You will notice that $1.50 for propane is 2/3 the cost of $2.25 diesel. So, if you can indeed get propane for next to nothing, by all means use it. But if you hit the 2/3 price, there is no savings to be had. This is what I have found and everyone else that I have encountered, whether they use my system or another one.
 
#11 ·
Here is my experience. A gallon of #2 is 140,000 btu. Divide that by 5 mpg, and you end up using 28,000 btu/mi. If the truck jumps to 7 mpg, it now uses 20,000 btu/mi. This means that the propane is providing 8,000 btu/mi, assuming that there is no magical efficiency gain. A gallon of propane is 91,000 btu. That divided by 8,000 is 11.4 mpg. At $500 for 10,000 miles at $1.50/gal, correlates to using 333 gal of propane. That is 30 mpg on propane. My real life results have been that the calculated mpg is very close to achieved mpg. At 11.4 mpg, the propane would actually be 10,000 miles/11.4 mpg = 877 gal at $1.50 = $1315 for LP. That plus the $3214 = $4529. No cost savings. You will notice that $1.50 for propane is 2/3 the cost of $2.25 diesel. So, if you can indeed get propane for next to nothing, by all means use it. But if you hit the 2/3 price, there is no savings to be had. This is what I have found and everyone else that I have encountered, whether they use my system or another one.
Am i reading your post right? The OTR truck probably used closer to 877 gallons of propane vs. the 333 gallons claimed?

WOW! That just burst my bubble
 
#10 ·
Very interesting info.

I was thinking about goining with a propane injection system for the fuel savings as well. The plan is to 'borrow' a bottle from work about once a week or less. The bottles at work are the standard forklift size. Not sure how many gallons that is (5???) Not gonna last me very long huh?
 
#12 ·
First off, nice boat! I haven't seen one of those in a while! I had one about 30 years ago. Brings back some good memories! :cool:

A forklift tank is about 8 gallons, on a light duty pickup, the propane consumption rate is about 60-80 miles to one gallon, so it should last you around 700 miles or so.

That post even confused me..It is not that complicated.With a variable system, an OTR truck will use one gallon of propane for every 30-50 miles .

There is no point to try to run the engine on propane. You could try to cut back some diesel fuel electronically. However, that can cause vehicle functionality issues, and reduced range of diesel fuel, and most owners and fleet directors are not interested in that.
 
#18 ·
First off, nice boat! I haven't seen one of those in a while! I had one about 30 years ago. Brings back some good memories! :cool:

A forklift tank is about 8 gallons, on a light duty pickup, the propane consumption rate is about 60-80 miles to one gallon, so it should last you around 700 miles or so.

That post even confused me..It is not that complicated.With a variable system, an OTR truck will use one gallon of propane for every 30-50 miles .

There is no point to try to run the engine on propane. You could try to cut back some diesel fuel electronically. However, that can cause vehicle functionality issues, and reduced range of diesel fuel, and most owners and fleet directors are not interested in that.
I'm not sure i follow you on the 700 miles per 8 gallon tank. Shouldn't it be more like 480-640 miles per 8 gallon tank at 60-80mpg of propane consumption?
 
#13 ·
In order to raise that OTR truck two miles to the gallon on diesel, it would take 877 gal of propane, not 333. When you add the btus of both fuels, they don't come up to enough at 333. Maybe I'm not taking into account the 'magical' efficiency gain that propane is supposed to give the engine. My experience and others have shown that no magic happens. It is a straight across swap of diesel btus for propane btus. Since propane has so many less btus per gallon, that is why the total gallons consumed will be higher than just running diesel.
 
#14 ·
I noticed you keep mentioning the phrase 'magical' efficiency gain...

It was my understanding that there is a slight efficiency gain due to the propane acting as a catalyst and burning all of the diesel in the combustion chamber, reducing the amount of wasted unburnt fuel
 
#15 ·
i agree. diesel burns complete in the low 90% , add propane and its close to 100% complete burn
 
#16 ·
All I can say is try it and see. I have run all different ratios of gas, both propane and cng, and when I compare total btus consumed per mile running diesel only and running diesel and gas, they come out the same. If there is an efficiency gain, I haven't been able to
measure it. Even so, if you get propane cheap enough, it will save you money.
 
#17 ·
All I can say is try it and see. I have run all different ratios of gas, both propane and cng, and when I compare total btus consumed per mile running diesel only and running diesel and gas, they come out the same. If there is an efficiency gain, I haven't been able to
measure it. Even so, if you get propane cheap enough, it will save you money.
 
#19 ·
yes, your correct, at 60-80 mpg, propane consumption, it would be approximately480-640 miles.

On average, the pickups using a 7.9 gallon 35 lb, 10x32 tank, go between 700-800 miles, some more, some less. With the flow varied and proportionate to boost, the amount used, is relative to what you run at for the majority of your driving. It's not just on or off. For example, if you run at lower boosts all the time, your mileage could be closer to 80-100 miles to one gallon, so 700 miles was a good average for comparison purposes.
 
#20 ·
I'll give an example of mileage numbers with that consumption rate. Let's say you can get 20 MPG on diesel only. That would be 7000 BTU/mile, since a gallon of #2 is 140,000 BTU. A gallon of propane has 91,000 BTU. If you would get 91 miles/gal on LP, that would be 1000 BTU/mi contributed by LP. You still need 7000 BTU/mi total minus 1000 from the gas leaves 6000 BTU from the diesel. 140,000/6000= 23.3 MPG as the new diesel mpg. If you got 60 MPG on LP, that would be 1500 BTU/mi from the gas, which would be 25.5 MPG on diesel. 30 MPG on LP would give you 35 MPG on diesel, and so on. When I ran LP on my Dmax, I averaged 64 MPG on diesel on a 1500 mile highway run. I got about 18 MPG on LP. The math says I should have gotten 18.9.
 
#21 ·
What digitally controlled systems are on the market right now and what are some of the pro's and con's of each?

I've currently got my eye on an MSD set-up
 
#22 ·
I have one in development, but it isn't finished yet. I hope to have it ready in three months or so. It'll have adjustable egt control of gas and diesel, and detonation sensing with fuel cutback. Both diesel and gas fuel curves will be adjustable by user with a laptop. Running cng, I average at least 130 mpg on diesel on highway runs, around 25 on cng.
 
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