Transport Partnership
U.S. ENVIRONMENTAL PROTECTION AGENCY
Energy
and
Fuel Savings
Gallons Saved
485 gallons
CO2 Savings
4.93 Metric tons
NewMPG
(from 6.0 mpg)
6.18mpg
Fuel Cost Savings
$1,680
Lou/-Viscosity Lubricants
A Glance at Clean Freight Strategies
Synthetic lubricants in the engine crankcase, rear axle, and transmission can
improve fuel economy by about 3 percent, saving nearly 485 gallons of fuel and
eliminating 5 metric tons of greenhouse gas emissions for a typical combination
truck each year.
What is the challenge?
Lubricants reduce friction and wear of critical vehicle systems including the engine, transmis-
sion and drive train. Without lubricants, the moving parts inside these systems would grind
together, causing heat, stress and wear. Conventional mineral oil lubricants may have too
high viscosity (internal friction that resists sliding and inhibits flow) to effectively slip between
and lubricate the moving parts of these systems, particularly in newer truck components that
are designed with close tolerances and tight fits. Conventional lubricants may also be heavy,
making it harder for pumps, gears and shafts to move. These effects create energy losses
and friction losses, and waste fuel.
What is the solution?
Low-viscosity lubricants are less resistant to flow than conventional lubricants, a property
that helps reduce friction and energy losses. Depending upon the application, low-viscosity
lubricants may also contain additives designed to withstand the extreme pressure (EP) that
could occur as the lubricant flows between tight-fitting parts. Low-viscosity lubricants may be
made from synthetic or mineral oil blends with low-viscosity and EP additives. Manufactur-
ers generally offer low-viscosity blends as "fuel economy" lubricants, since the fuel-saving
potential of these products is significant. A national trucking association reports that synthetic
transmission and axle lubricants can improve fuel economy by 0.5 percent in the summer
and 2 percent in the winter (viscosity is temperature-dependent.) A paper published by a pro-
fessional engineering society found that synthetic engine and transmission lubricants could
improve fuel economy by 5 percent, with greater gains at lower speeds. Another paper from
this same organization reports that synthetic gear lubricants can improve fuel economy by
about 3 percent. European research demonstrates a 3 to 5 percent gain in truck fuel econ-
omy using low friction engine lubricants and a 1 to 4 percent gain using low friction transmis-
sion lubricants.
Synthetic and semi-synthetic lubricants typically cost more than conventional mineral oil
lubricants. Truck service stations suggest that semi-synthetic oils cost about 50 percent more
than conventional mineral oils. However, for most trucks, the fuel cost savings generally
outweigh the higher product cost. Furthermore synthetic lubricants may extend the interval
between lubricant changes therefore further reducing costs of truck fleets.
SmartWay Transport | EPA^t20-F09-041 | www.epa.gov/smartway | 734-214-4767 | smartway_transport@epa.go
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Low Viscosity Lubricants
1.
D
•4
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"-••s^ ""-s^
1 Trucking companies
should consider using
low-viscosity lubricants
to improve fuel economy.
Synthetic oils are com-
patible with most truck
systems, save fuel, and
should provide net cost
savings.
2 Before switching
lubricants, trucking
companies should en-
sure that the product
suits the intended
application. Always
check manufacturer
specifications before
switching engine,
transmission or drive
train lubricants.
~~~^_
3 Consult the manu-
facturer's vehicle and
parts owner manuals
and service manuals
for information and
recommendations
on lubrication speci-
fications and proce-
dures. Lubricating oil
manufacturers and
lubrication guides can
provide information
about product applica-
tions.
^•-v.
4 Trucking associations,
equipment manufacturer
associations and truck-
ing industry publications
may provide additional
information and case
studies about the ben-
efits and uses of various
lubricants.
Savings and Benefits
The combined effect of low-viscosity synthetic engine oils and drive train lubricants can improve fuel economy by at
least 3 percent, saving nearly 485 gallons of fuel per year for a typical combination truck. Even with the higher cost of
the synthetic oil, truck owners can save more than $1,680 in fuels per year. Additional cost savings may be possible
due to reduced wear and maintenance. Switching to low-viscosity lubricants will reduce greenhouse gas emissions by
4.93 metric tons per year for each truck.
Page 2
SmartWay Transport | EPA-420-F09-041 | www.epa.gov/smartway | 734-214-4767 | smartway_transport@epa.gov
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