Propane=+Economy?

**Landscapeman** · 08-06-2008, 09:30 PM

What kind of realistic MPG increase will a propane system give? I am looking at anything that increases economy.

Tamperman · 08-06-2008, 09:55 PM

I would like to know this also. My local propane salesman says it's not worth the trouble. I would like to hear a pro weigh in on this tho'.

gr8shot · 08-07-2008, 11:23 AM

I imagine there's a reason hardly anyone does it. IDK though.

ironcrossmike · 08-07-2008, 03:11 PM

I thought it would only help if you were overfueling the engine anyway. Otherwise I would think it would cause a lean condition. Not sure though.?

**NASTYHAULER** · 08-09-2008, 05:53 AM

I've heard that it's generally a 10-15% increase in mileage so roughly 1-3 MPG increase.

**Landscapeman** · 08-09-2008, 08:05 AM

Quote:

Originally Posted by NASTYHAULER

I've heard that it's generally a 10-15% increase in mileage so roughly 1-3 MPG increase.

I have heard the same. At that point it is not worth the cost.

BigGrnJeepTug · 08-09-2008, 08:50 AM

You MAY see 3 mpg gain with propane, but you will gain a good bit of power depending on the jet used. Propane just assists diesel complete its burn. This is very helpful if you have a tune thats spewing unburnt diesel, but if you have a tune that isnt spewing soot theres nothing there for the propane to help burn so you gain only the effects of the propane burning. Banks has a writeup on his website aboug propane and nitrous. Both do about the same thing but nitrous cools the air charge much better than propane so your power increases are greater. IMO the gains of propane are so heavily outweighed by the cost its not worth it unless power is what your after. Water methanol is another thing you could research. Snow performance makes a kit the they SAY gives 1-3mpgs. Water is damn near free and if gets a claimed mileage increase to that of propane there is no second guessing. You have the EXACT setup i have but in LBZ. I get 22-23mpgs highway and am always trying to get more. I have found they lvl2 give the best fun vs. economy on my PPE.

BigGrnJeepTug · 08-09-2008, 09:13 AM

Propane - Wikipedia, the free encyclopedia Methanol - Wikipedia, the free encyclopedia . Take a look at these links. Bear with me im going to try and prove a point but im not a teacher so this could sound bad. All fuels need oxygen to burn so to increase oxygen you need to supplement. In the case of a turbo diesel we turbocharge. This compresses atmospheric air and provides more oxygen, but only 19%(this is what atmospheric air contains). So you can supplement further by bringing other oxygen supplying fuel to the table. Methanol and Nitrous OXIDE both have one atom of oxygen per molecule. Methanol and nitrous both cool the intake charge. They both have oxygen molecules so they will help burn but methanols oxygen is used when it burns its own hydrogen. NO's oxygen is free to bond with any diesel "molecule" to complete the burn. Nitrogen is inert and just cools when depressurized from the tank.So you would probably see the best mileage increase from nitrous but its VERY expensive(so is propane). Methanol is cheap but isnt near as efficient as NOS. Bang for the buck get a water/meth kit and start tinkering. Im in hurry to leave the house. I hope this in some way is understandable. SOMEONE HELP EXPLAIN WHAT IM TRYING TO SAY!

delong_1 · 08-09-2008, 01:13 PM

i have heard some good things about cng (compressed natural gas) around 70 cents a gallon and better mileage than with propane by far

signman1984 · 09-10-2008, 10:09 PM

I saw an episode on "Trucks" about a year ago... before I even had a diesel, and the host put a propane system on a new diesel truck. He dyno'd it before and after and the system was a bullydog system I think. fairly simple to install, the results were much more hp. and actually the propane had some additional benefits which were a cleaner burn... and the engine ran MUCH cooler. I thought this was very odd. In anycase it was awhile back but I just remember being impressed. sounded like a no loose senario IMO.