Curious on price of kits, diesel fuel mileage and propane mileage before needing refill. Thanks.

 

check swampsdiesel.com faq's,

 

Thanks 250turbo, that didn't sound too good. The more I find out the less enticing this is. If there was substantial mpg gains, it might be worth the risk but I am not looking to make extra power so this mod doesn't sound worth pursuing.

 

Diesel-Propane dual fuel systems can work well but the low-tech systems are very risky. Propane's critical compression ratio is ~12:1 and its use must reduced as engine loads increase or detonation will result (see Dual Fuel Fumigation). I expect that Swamps Diesel Performance has had experience with the low-tech systems. A diesel-propane system that uses a fuel map to control propane supply is much safer and the only two that I'm aware of that have a fuel map are the EcoDiesel System and the Diesel Magnum.

Diesel Dual Fuel Conversions

 

Any updates to this post? End up doing it? Seems interesting.

 

I haven't done anything with it. I was hoping for like 8+ mpg gain to make the expense and risk worth it but it only sounds like 2-3 gains. Probably better off to first make the whole truck as efficient as possible first, like synthetic fluids, programmers, transmission stuff and the other usuals.

 

Yea, sounds about right. Good call.

 

I bought a superchips digital propane injection system thinking that I could "make it work" with my IDI engine but now I'm not so sure. I chose this system because of it's reputation of being the safest propane injection system but it requires an ECM which mine doesn't have. Now I'm either looking for a newer F250 7.3 PSD truck or selling my kit. BOOOOOOOOO. I'll keep looking for a newer truck.

 

z scpaes, what was your reason for wanting to run propane? More mileage or power? Any claims on mileage increase? How much was the set up you bought and is it a complete system or do you need to buy more? Thanks.

 

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

 

My intrest is mileage, Not HP. the horsepower gains are welcome but I won't be tuning my system to create big HP numbers. This is the most advanced "digital" propane injection system I've been able to find. Superchips Propane DPI Kit mine is the SCP-4815 uses a closed loop ECM and constatnly monitors parameters including engine temp, rpm, boost pressure to control flow. This system is mapped and programmable to your application. Only thing you need for this system is a tank.
I'm very new to the Propane injection systems and all I know is what i've read over the last 2-3 months. I did my homework before I bought this system when it comes to safety but I should have researched more about the truck I bought to put it on. 1991 F250 are not ECM controlled and my system will not work with this truck. yeah I know!
I have a landscape company and I tow my skidsteer and mowing equipment over a 60 mile radius. at 4MPG inrease I'll cut my fuel expense by about 25% after purchasing the propane. I have an 80gal tank to be mounted in the bed but it will take up alot of room and I have to have it approved before I can have it filled.
Thanks for the positive feedback on this topic Farmport, I haven't been getting much of that, concerning propane. at least not on this site.
Oh yeah, I posted some of the "claims" on fuel mileage for this kit in another thread. I got hit with speculation right away. I only posted what I had read and now I can't find the ad that I quoted so I won't be handing out any more "false information" You can find some info out there by searching superchips DPI

 

The Superchips system sounds great but as you say it requires an ECM system. I take it your engine is indirect injection? Is it turbocharged? Indirect injection engines by design are not very efficient. There is a way of gaining economy with non-ecm controlled fuel injection, but there is a downside. If a decent propane system is installed then it is possible to cut back the diesel pump until the diesel propane horsepower output is the same as it was on diesel alone. This means that for any given throttle position less diesel is used. Since propane greatly improves combustion efficiency you should get significant cost savings. This requires that propane is used in all engine operating ranges including idle and if you run out of propane you will have less power than originally on diesel alone. This has a good chance of working well on an indirect injection engine as the less efficient the combustion, the better propane works. If the engine is turboed there is another way of achieving this without sacrificing diesel only power. I think at this point I should establish my cred. I have installed around 600 propane systems on vehicles including around 100 on diesel vehicles here in australia using my own technology. My diesel propane system has always been fully electronic and does not depend on an ECM being present. My system is not available in the USA so I don't have any commercial interest as far as these forums are concerned.

hope I am helping and not confusing.

 

Very Good info. My engine is the IDI and it's not the turbo engine. I'm looking for mileage as this is a work truck and I tow about 6000lbs with it. The propane injection system was interesting to me for it's clean fuel properties and it can very ver y effective in producing mileage increases. I hope for more propane users to come to this site.

 

Diesel-propane systems are stand-alone systems and do not require an interface with the vehicle's ECM. However, mapped propane systems (ie, with an ECM) work much better than much simpler on-off or proportional-addition systems. Diesel-propane systems generally rely on boost pressure for determining the amount of propane to add. Systems for a non-turbo engine would have to use another method (like throttle position) instead.

It is important to cut back on propane as loads increase because of the risk of detonation. This means that lightly loaded vehicles can use proportionally more propane with the resulting greater fuel cost reduction of using a lower-priced fuel. Some systems can even supply propane at idle.

If you have CNG available, the cost savings are much greater than using propane. This is because (1) CNG is usually much cheaper than propane and (2) much greater amounts of CNG can be used due to its higher octane rating.

 

I used a home made propane system on a idi I had. When I turned on the propane to maintain speed I would have to let off on the pedal. Yes you use less diesel but now you have to buy the propane. With diesel at $3 and it just cost me $15 to fill a BBQ tank we are screwed. With running dual fuels you may get a slight increase with a better burn but unless you can get propane for free I don't see any big gains