Why Your Fleet Needs AG&T Conversions

USNGV Vehicle Conversions

Some new vehicles can be purchased “Natural Gas-Ready.”  However, the quickest way to transition a fleet to NG operation is to convert existing vehicles.  Since conversions from gasoline or diesel to natural gas have been done since the 1980s, there are already aftermarket kits available for many vehicles.  For example, the figures below show a kit for gasoline to CNG conversion.  The regulator [2] is attached to the fuel tank to reduce tank pressure to ~125 psi.  Fuel is then fed to a parallel fuel rail [3] and to new, secondary injectors plugged into an adapter [4].  A wiring harness [5] plugs into the factory engine-control unit and intercepts throttle information, sending it to a new fueling computer [6], which slightly alters the data and passes it to the LNG/CNG injectors [7] through a parallel wiring harness.  (Please see illustrations below.)



Two Fuel Rails, two sets of Fuel Injectors, both feed the same intake port.

Natural Gas Vehicle conversions must be properly installed and maintained on customer vehicles by Natural Gas Conversion experts. CNG aftermarket vehicle conversions are mature. The primary difference between a CNG conversion and LNG conversion is the fuel tank itself, since the fuel that enters the engine cylinder is the same in either case. All natural gas vehicle conversions require Environmental Protection Agency certification. If the conversion is to be used in California, it must be approved by the California Air Resources Board as well. USNGV takes care of all certifications to make sure your vehicles can be operated legally and safely.


USNGV has your back!


LNG is the most beneficial form of vehicle natural gas fuel.  Based on the same tank volume, LNG provides three times the range of CNG.  A gallon of LNG weighs about half as much as a gallon of gasoline or diesel.  It does require more volume to match the energy of gasoline and diesel (1.55x and 1.7x respectively).  This means that a 100 gallon diesel tank could be replaced by a 170 gallon LNG tank, but the end result is that the lighter LNG fuel won’t change the vehicle weight much.  The pressurized tanks in which CNG is stored are almost four times as heavy as an LNG tank for the same amount of stored energy – and the former take up far more space. 


LNG is stored in a government-certified tank that has a vacuum-jacketed insulation layer, much like a Thermos™ bottle.  The US Department of Transportation requires that all mobile fuel tanks be crash tested to confirm that the risks of fire from a punctured tank satisfy very conservative levels.  It is interesting to note that LNG is not flammable, and will only combust once it warms up enough to vaporize and mix with a lot of air.  Even when mixed just right and ignited, the resulting flame is far less dynamic than gasoline!


LNG emissions are cleaner than CNG.  The chilling stages in USNGV’s processing equipment remove the excess nitrogen and heavy hydrocarbons that are typically found in typical pipeline natural gas used to make CNG and LNG.  That means that emissions from burning USNGV LNG are almost non-existent.


LNG is considered by many to be safer than CNG because it is stored at low pressure.  An LNG storage tank in a vehicle or at the station holds its pressure at about 100 psi while a full CNG tank is 3,600 psi.  If an LNG vehicle is not driven for a few weeks, the fuel in the tank will warm up and start to build up more pressure.  However, the tank will automatically vent at around 150 psi to reduce its pressure.  Obviously this is not good for the atmosphere, so LNG vehicles should be used frequently enough to prevent this, or at least connected to a USNGV fueling station so the fuel tank can be refreshed.


Why should you choose USNGV to provide your LNG?


Most LNG stations have to vent some LNG to the environment when they fuel a vehicle and when the tank is just sitting idle as their LNG warms up.  They have no re-liquefaction capability on site, so they must vent the fuel or add a compressor to store it for CNG vehicles.  Venting LNG to the environment is costly and environmentally unsound, a practice that will legally be prohibited in the near future.


USNGV stations capture the excess pressure (vaporized fuel) from vehicle fuel tanks and re-cool the tank to an optimum temperature.  When captured, this vaporous fuel is actually measured so its value is fairly traded for liquefied fuel, and the station also turns the captured vapor back into liquid.  Of course, if the station were to not be utilized for a few weeks, it would automatically keep its own storage tank cold to ensure that there is no venting to atmosphere.


One additional benefit - other LNG suppliers store their fuel in large above-ground 15,000 gallon tanks that are difficult to permit. This permitting difficulty is due to the large volume of fuel that must be trucked to each station which, by law, requires minimum distances from property lines plus a large area around the tank for delivery tankers – a challenge for small fleets.  Since USNGV stations can make what the fleet needs each day, their storage capacity eliminates these difficulties.






USNGV understands that fleet owners do not have time to become Natural Gas Vehicle (NGV) industry experts. They need to cut fuel costs without spending money up-front or taking on additional risks.  In other words, fleet owners want to buy fuel for less money, without the hassle of managing an additional operation. USNGV, using its knowledge, experience and the recent technological advancements made to NGV equipment, can now design and implement meaningful NGV programs for your fleet. These programs can save almost every fleet substantial amounts of money through reduced fuel and maintenance costs.


USNGV offers turn-key programs that allow fleets to pay for their NGV programs within their current per-gallon fuel budget. USNGV assures, not just that the vehicles and stations operate satisfactorily, but also that the fleet could save up to 15% on its fuel purchases!

US Natural Gas Vehicles 1850 SW Boxwood Lane

Dallas, OR 97338 

(707) 548-6560

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