Diesel + lpg = big mpg

[rmay635703]

LPG saves nothing over diesel and can detonate.

CNG is about half or less the cost of diesel, and it can notdetonate.

I would not waste time on lpg

[teoman]

Cng requires high pressure tanks and is more of a burden. Lpg already has fueling stations all over.

Besides that cng is more advantageous.

In some places the pricing of the fuel is what provides the benefit.

LPG 3
Diesel 4.5
Gasoline 5
CNG unavailable at the gas station

Money units per liter where i live.

[skyking]

I notice the OP is from 2012, and is long gone now. I suspect it proved to be the low yield burden that many have found it to be.
When it works out, it is usually on pickups that have spare bed space and room for the plumbing, and when the diesel to propane price is closer to 2:1 or better.
Carbon is carbon; Diesel weighs 7.1 pounds per gallon and propane 4.24 pounds per gallon. This is a ratio of 0.597.
Now look at the BTU of each fuel:
diesel = 128700 LHV ( Low Heating Value ), propane = 83500 LHV
This is a ratio of 0.648
Detonation has not been a problem I have heard of when used at the low power settings of cruise.
In a car I would not touch it at all ever, as it involves keeping a pressurized container and potentially leaky plumbing inside your car 24/7/365. I don't mind bringing a bottle home for the barbeque a few times a year, but the other condition sounds a little too risky for me.
If you go the proper route and install a whole certified and vented LPG system, they often use the space from the standard fuel tank for that installation. Not so hot when you want to burn both
I kicked it around when diesel was over $4 and propane under $2, for my 12V Cummins truck. In the end I found it did not work for me, as I don't daily drive a heavy truck when it is not needed. Even my sad Toyota Camry approached 30 MPG on road trips and close to 28 mixed driving. Nothing I could do to the truck was going to touch that.

[oil pan 4]

Agreed. I tested it back around 2007 or 2008 and found it to not be worth the trouble.
I would rather use water methanol.

[rmay635703]

Originally Posted by teoman

Cng requires high pressure tanks and is more of a
CNG unavailable at the gas station

Money units per liter where i live.

Opposite is true here in Wisconsin, every main city has CNG at the gas station.
LPG is only available in back lots of specialty providers that have limited hours

[skyking]

that's the problem with CNG I looked at the CNG maps here:
CNG Stations | Refueling | Prices | Map
In my area, it is very sparse on the ground. OK is like the CNG capital of the world

[teoman]

Originally Posted by teoman

Cng requires high pressure tanks and is more of a burden. Lpg already has fueling stations all over.

Besides that cng is more advantageous.

In some places the pricing of the fuel is what provides the benefit.

LPG 3
Diesel 4.5
Gasoline 5
CNG unavailable at the gas station

Money units per liter where i live.

Well, the economic situation over here has gone for the worse.
New costs

lpg 3.5
Diesel 6.3
Gasoline 7

Monetary units. And salaries have not increased.

Still considering LPG for a diesel. I found a second hand complete kit for 50 bucks. I want to hook it up to a gasoline injector and inject in liquid form after the turbo or intercooler.

If i find that it absolutely has to be in gas form, i would consider injecting it inside a radiator and use it for AC.

Oilpan what did you not like about the system. And how did you implement it? Was it sophiaticated or just bbq bottle and valve?

[oil pan 4]

I built mine for testing only.
I'm pretty sure you need gas or a way to regulate liquid pressure.

[teoman]

I am not sure, a fuel pressure sensor, and the injector can be pulsed accordingly.

That way one would also have the benefit of water injection (lowering intake air temperatures).

Did you not mention 9 deg C was the lowest temp for diesel intake, lower and combustion suffered?

[teoman]

The kit i am buying has a gassifier that circulates coolant. But I hope not to be using it to benefit from the cooling effect.