Update 5/27/14

I haven't updated in some time, but things are going well.  I have driven about 22,000 miles in the eight months since I purchased this vehicle and there have been no mechanical issues since the Impco system update.  Rather than attempting to update several different posts, I will cover all that I know within this posting.

Background Info

Admittedly, I can be a dreamer.  When a fragment of one of those dreams lands into the part of my mind that can become obsessive, it can create an issue for me.  This is what happened when I first heard the words "Haynesville Shale".

The Vehicle

I ended up purchasing a 2010 Ford F150 supercrew 4x4 which had been converted to run on CNG and gasoline.  This is called a "bifuel conversion" in that it runs on both gasoline and CNG as opposed to a "dedicated CNG" which is CNG only.  Encana is an oil and gas production company which has been active in the Haynesville Shale, especially in the Red River Parish area. This truck had been an Encana fleet vehicle.

The Tank

When we fill up, natural gas is delivered from the pump into the storage tank on the vehicle.  The pump compresses the gas into the tank to a preset pressure (not volume), usually 3,600 psi.  It is easy to think that when we are filling up an empty 23 gge tank that we should get 23 gge of natural gas into that tank, but that isn't the case. There are a couple of points to understand so that you don't feel disappointed.

Impco System Update....Post updated 12/20/13

I bought this truck in September.  I noticed that as the temperature dropped over the next two months, I would sometimes have trouble when operating in CNG mode.  The engine would sometimes miss.  Sometimes it was barely noticeable, and sometimes it was so severe that it I had to switch it over to gasoline.  Once on gasoline, it ran fine.  I contacted Impco Technologies and after some discussion with their automotive technical support department as well as emailing photos of engine components it was ascertained that there is an update to the CNG system on this truck that had not yet been done.

Fast Fill vs Slow Fill....Home Refueling Options

When we use a CNG refueling station, the gas is pumped into the tank at a rapid pace so that we don't spend all day at the pump.  This is known as a "fast fill".  We have previously learned that due to temperature changes creating volume changes that there is a decrease in pressure once the CNG is pumped into the tank to 3,600 psi.  This makes the fast fill less efficient in achieving the goal of getting the most CNG into the tank per fill.  As a result, we end up filling up with greater frequency which is a hassle as well as more expensive in that we burn unnecessary fuel going to and from the pump.

Feedback/Suggestions for CNG Vehicle Designers

I will update this entry periodically if I notice something that would be relevant for those vehicle designers who might cruise the internet for research material and happen to stumble into this blog.