Conversion to GFS Gaseous Fuel typically results in similar performance levels
in terms of engine stability, HP, torque and response.
Vehicle duty cycle is the most important variable for determining average
In addition to duty cycle, gas composition, charge-air
temperature as well as ambient conditions (temperature and altitude) may also
play a factor relative to the knock limit of the air-gas mixture.
moderate to heavy engine loading (over the road conditions) will typically yield
gas ratios between 60-75% (assumes high quality natural gas). Lower average
engine loads (stop and go / high traffic conditions) will typically limit gas
ratio to between 50-60%.
Engine Lube Oil
Unless otherwise indicated by gas composition, no changes in engine lube oil
specification are required for Gaseous Fuel operation. Natural gas burns with
minimum particulate residues so that engine oil may be kept cleaner during
Gaseous Fuel operation.
This can possibly lead to longer average intervals
between lube oil and oil filter changes and extended periods between engine
overhauls. No changes should be made to the OEM's recommended service intervals
without complete engine oil and wear analysis and consultation with the OEM.
Engine Operating Temperatures
Engine heat rejection rates while operating in Gaseous Fuel mode are largely
similar to 100% diesel performance. Engine exhaust gas temperature, coolant
temperature, oil temperature and manifold air temperature levels remain within
the limits set by the engine manufacturer.
Because the Gaseous Fuel System utilizes a low restriction air-gas mixing device
and maintains the excess-air operation of the diesel engine, net fuel efficiency
(specific fuel consumption) is normally equivalent to 100% diesel operation. For
each unit of diesel fuel displaced during Gaseous Fuel operation, a calorically
equivalent unit of natural gas will be needed to maintain engine power.
Gaseous Fuel operation will typically reduce production of nitrogen oxides,
sulfur oxides, reactive hydrocarbons, carbon dioxide and particulates
Exhaust opacity levels (visual emissions) are also typically reduced. For
emissions sensitive applications, a 2-way oxidation catalyst is recommended.
Installation of the Gaseous Fuel System does not generally impact factory engine
warranties. Because the engine is not modified from the original design, OEM's
typically take the position that the full force and effect of their warranty
will remain valid after conversion to Gaseous Fuel .
Gaseous Fuel System Warranty
Primary components of the Gaseous Fuel System including mixers, electronic
controllers and gas train components are covered by a one year limited warranty.