Winter Fuel Tips


  • Replace fuel filters at manufacturer recommended intervals.  Particles in the filter make it easier for wax to gel.  Use the highest OEM accepted micron filter possible.
  • Keep your fuel tanks full and free of water.  Cold air on top of warm fuel creates condensation.  This can be reduced by limiting the amount of space in your tanks.
  • Test any bulk tanks for water.  Water freezes faster than the wax in the fuel.  If your fuel has 100 ppm or higher water content, it should be treated with a drying agent.
  • Drain fuel water separators weekly and be sure to monitor them even between scheduled maintenance.
  • Open the drain at the bottom of the fuel tanks to drain off any water &/or sediment.
  • If your vehicle is going to be idle for long periods of time (4 hours or more) you may want to install a fuel heater or find heated parking.  Moving liquid takes longer to freeze than stationary liquids.  Keep your fuel moving or keep it warm.
  • Tighten all fuel tank mountings and brackets. At the same time, check the seal in the fuel tank cap, the breather hole in the cap, and the condition of the flexible fuel lines.  Repair or replace the parts, as necessary.
  • After your vehicle has been off the road for an extended period, start and let the engine idle for 30 or more minutes allowing warm fuel to return to the fuel tanks to break up any wax buildup.

DEF (Diesel Exhaust Fluid) and cold weather

  • DEF is required to remain pure to operate correctly.  Additives should never be added to DEF.
  • DEF freezes at 12 degrees F.  The 32.5% urea concentration in DEF allows both the urea and water to thaw at the same rate, therefore keeping the solution from being diluted or over concentrated.
  • SCR systems are designed to provide heating to the supply tanks and lines during normal operation.  If the DEF freezes when the vehicle is idle, normal start-up and operation will not be inhibited.  The DEF will thaw as the vehicle is operated.  Freezing and thawing will not degrade the product.

If you need additional help or suggestions on your winter fuel program, please contact Conor Proud at 267-482-6159 or  For further help with your fuel management program or to lower your fuel cost, visit us at