The number
one question we get asked by heavy duty truck fleet buyers when it comes to comparing
natural gas engines to diesel engines is, “how far will it go?”
Fuel
economy, the distance a vehicle can travel per gallon of fuel is only one piece
of the puzzle; the other is range. Range is how far a vehicle can travel before
you need to refuel, when it’s carrying a full load of fuel under average
conditions. Most people attribute the range of a vehicle solely to the engine:
the common misconception is that range is determined by how much fuel the
engine burns.
But range
isn’t simply calculated by the engine’s thermal energy. Many aspects of the
vehicle influence its fuel economy, such as: vehicle aerodynamics, vehicle
load, terrain, driver habits, and more.
This
diagram shows some of the factors that contribute to a vehicle’s range, and the
opportunities for improving those areas.
When all
else is kept the same (such as load, terrain and surroundings), the Westport HD
engine achieves approximately the same fuel economy as its diesel equivalent.
Jonathan
Burke, Vice President, Global HD Market Development comments about the range of
natural gas engines in heavy-duty trucks:
Many fleets initially
object to new technologies for a wide variety of reasons, many of which can be
resolved with simple clarifications of fact versus what their perception may be
– range anxiety, especially for heavy duty transport applications, is one of
these. Simply put, all motorised vehicles have range limitations. Whether it’s
gasoline, diesel, natural gas, hydrogen FCV, electric or even nuclear!
A common comment we hear
from fleets is that natural-gas vehicles don’t carry much fuel, therefore they
can’t travel nearly as far as their existing diesel fleets. This is false.
Heavy LNG vehicles can carry as much as 600 to 700 miles of fuel onboard.
Surely drivers will need to stop for a break before they drive that far!
Heavy CNG vehicles
commonly carry 300 to 400 miles of fuel, which is still enough to travel the distance they achieve
with diesel or gasoline. The main issue causing range anxiety is
that with diesel, the accepted practice is to carry enough fuel to last several
days worth of driving. This reduces the amount of time the drivers need to stop
and refuel at stations that are not affiliated with their fleet, which are
often more costly. There is a simple solution – plan your routes differently
and arrange your fuelling stops to coincide with the limitations of the
vehicle’s onboard capacity. Although this may seem like a significant
undertaking, in many cases it is not. Most large fleets already employ very
sophisticated fleet management software that can easily provide the tools to
plan routes for a comparable natural gas vehicle. This is a small price to pay
given the significant economic and environmental benefits offered by operating
on natural gas.
When given the choice, a
simple operational alteration in exchange for lower operating costs, lower
emissions and the pride of running on domestic fuel seems pretty simple.
Range limitations occur with any vehicle. The best way to
cure range anxiety is to ensure that for all possible travel conditions
(weather, terrain, speed, etc.) drivers have enough fuel to complete their journey.
If the route will be longer than the truck’s range, then it’s easy to
coordinate the driver’s breaks with CNG fueling stations, just like you would
with diesel or gasoline.
