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propane injection?

6K views 22 replies 10 participants last post by  Dbtravis 
#1 ·
anyone doing propane? What kind of mileage you guys getn? were in the propane buisness so it would be a no brainer for us i think
 
#2 ·
just do it if you get propane cheap but it has 2/3rds the energy diesel does so unless you can get it for atleast 2/3rds the price of diesel then don't do it for the mileage gains but performance it is more fuel so there can be benefits sometimes.
 
#3 ·
Depending on the system you use, and the amount of propane it uses.

Fuel cost savings resulting from operation with propane fumigation, will vary according to the respective cost of each of the fuels. If there is a significant cost differential between the cost of diesel fuel (per gallon, liter, etc.) and the equivalent quantity of LPG (heat value basis) in favor of the LPG, significant fuel cost savings would result. The closer the fuels are in price, the lower the fuel cost savings will be. In addition to fuel cost savings, engine maintenance savings may also contribute to the economic benefits.
As well as the federal alternative fuel tax credit of .50 a gallon.

Many LPG companies are using it on their bobtails, and company truck such as Blossman Gas, in the Southeast, Proulx in the Northeast, Dufor Petroleum, in the South.
 
#5 ·
#8 ·
Fuel cost savings from propane injection vary according to a number of factors.
1. Engine load. A light vehicle just running around and doing normal unladen stuff will benefit from power, torque and general driveability improvements but seldom fuel cost savings. This doesn't mean there are no efficiency gains - there are - generally the extra power comes with no fuel cost increase.
A vehicle towing a heavy trailer, unless the engine is at full power all the time, can have significant gains. An 05 F250 I did a couple of years ago went from 4.5km/litre towing a 5th wheeler on diesel alone to 6.2km/litre on diesel/propane and was up 30% in power. It was using 20% propane so any way you look at it there were good savings. Another example is an 8tonne Mitsubishi truck and trailer that carts empty containers from a port to a terminal about 30miles away. Saves $2000/month. Larger diesels always seem to benefit more.
2. The way the propane is controlled. Some systems out there do not have electronic control of propane rate but rely on linear delivery of propane according to boost. More boost, more propane. This sort of works but cannot be efficient over the whole operating range of the engine. There are a few other factors that need to come into play such as air flow, available oxygen, throttle position or load.
3. Engine type. All diesel engines respond to propane but turbo engines the best. Everything from old mechanical injection systems to the most modern common rail elctronically controlled engines respond well.
4. To get the best out of a diesel/propane system it should be set up on a dyno using a wideband AFR unit. the minor cost of this is well worth it as it will make even some of the more rudimentary systems work "OK". It also instantly identifies if there is any fuel problem with an engine. If diesel mixture's are too rich to start off with the propane just won't work.

cheers
 
#11 · (Edited)
Are you talking electronically injected? Mine is injected over boost pressure so there is no programmer required. Take a look in my garage and you will see how it is set-up.
 
#10 ·
not quite sure what you mean by programmer but if you are referring to electronic control of the propane then yes it is very important to get the best results and to avoid overfueling with propane or wasting it. A mechanically regulated system will work so long as it is optimised using a dyno and AFR unit but cannot work efficiently as most of these use boost alone as a means of regulating propane flow. This is not valid as boost remains static once the wastegate has opened over quite a range of throttle settings and rpm and during this diesel AFR changes very dramatically. Even if airflow is also used (via a venturi) the widely varying AFR's are not compensated for. In saying all that diesel propane is fairly forgiving so a mechanical system of regulation optimised for the usual engine load is not bad.
 
#17 ·
Give marc@delucafuelproducts.com a call. Marc also has CNG injections systems, based on the price difference, CNG offers a better savings vs diesel or propane
 
#19 ·
I agree. I'm still looking on ebay or craigslist for a useable tank....
 
#20 ·
My Dmax running w/o a trailer would do 4 gal of propane to 1 gal of diesel. Under load you can't do nearly that due to detonation. Typically even towing I could double my diesel mileage. Since you can get the gas at cost, it will definitely save you money. It is hard to save money with it these days if paying retail unless bought in large quantities. I don't have lp in my truck anymore because I put 3 18 GGE CNG tanks in it. Once I have the electronic controller done, I may be able to do up to 5:1 at light load. On CNG I can average more than 10:1 w/the controller. In fact, during some testing I got up to 25:1.
 
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