Transport Partnership
                                A Glance at
            Clean Freight Strategies
Low Viscosity  Lubricants
   Synthetic engine and drive train lubricants can improve fuel economy by about three percent, saving nearly 500
   gallons of fuel and eliminating five metric tons of greenhouse gas emissions for a typical combination truck each
  What is the challenge?
  Lubricants reduce friction and wear of critical vehicle
  systems including the engine, transmission 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. Manufacturers 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 two percent  in  the  winter
  (viscosity is  temperature-dependent.)  A  paper
  published by  a professional  engineering society
  found  that  synthetic  engine and transmission
  lubricants could improve  fuel economy by five
  percent, with greater gains at lower speeds. Another
  paper from  this same  organization  reports that
  synthetic gear lubricants can improve fuel economy
  by  about   three   percent.   European   research
  demonstrates a three to five percent gain in truck fuel
  economy using low friction engine lubricants and a
  one  to  four  percent   gain  using  low  friction
  transmission 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.

      The results are in ...
      The combined effect of low-viscosity synthetic engine
      oils and drive train  lubricants  can improve fuel
      economy by at least three percent, saving nearly 500
      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 $500 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 five metric tons per year for each truck.

      Next steps
      Trucking companies should consider  using  low-
      viscosity  lubricants  to improve  fuel  economy.
      Synthetic oils  are  compatible  with  most truck
      systems, save fuel, and should provide net  cost
      savings.  Before switching  lubricants, trucking
      companies should ensure that the product suits the
      intended application.  Always  check manufacturer
      specifications before switching engine, transmission
      or  drive train lubricants. Companies should  also
      consult manufacturer's  vehicle  and parts owner
      manuals and service manuals for information and
      recommendations on lubrication  specifications and
      procedures.  Lubricating oil  manufacturers  and
      lubrication  guides  can  provide  information about
      product  applications.   Trucking   associations,
      equipment manufacturer associations and trucking
      industry  publications   may  provide  additional
      information and case studies about the benefits and
      uses of various lubricants.
U.S. Environmental Protection Agency ^ Office of Transportatia
 February 2004. EPA420-F-04-OQ6. ^ For more information,, visit: www.epa.gov/smartway