According to Mel Kirk, vice president of maintenance operations Ryder Systems Inc., diesel fuel and diesel exhaust fluid will freeze in extremely cold temperatures. This is a problem because the regeneration process that is required from an emissions control standpoint will not execute at certain temperatures.
“The first step is for fleets to be aware of this issue,” he says. The next step is to make sure you have the right fuel in the vehicle. “There is a winter weight diesel fuel mix that folks in Minneapolis and Canada switch to in the September-October-November time frame, because they know the risk of the temperatures dropping fairly significantly. That fuel gives them the best chance of keeping the vehicle on the road.”
However, fleets that typically drive in more temperate climates may not be aware of the need for winter weight fuel as they head north. “They may still have a summer blend in the tank and as they go north it will freeze just as soon as they stop the vehicle.
Kirk says fleets should also consider adding fuel additives to enrich their fuel when in cold climates. He also urges fleets to try to keep at least a half a tank of fuel in the vehicle when driving in winter conditions. “When you are going south to north, you never know when you are going to have road closures. The significance of having half a tank of fuel when you are in a situation where you can’t move is because of the emissions control apparatus on the vehicles. You have to keep the vehicle running through these extreme temperatures because the vehicle has to hit a certain temperature threshold to go into its regeneration cycle.”
In normal weather conditions idling will allow a vehicle to reach the temperature threshold necessary for regeneration to occur, “but when you have got temperatures that are constantly below zero it takes more energy to get that vehicle up to that sustained temperature. You can’t do it just by idling or warming the engine with a block heater. You have to run the vehicle on the road. You want to have fuel in the vehicle to make sure you are able to do that even if you are in an environment where you can only move a few yards at a time,” he explains.
He also says that when over nighting in extreme weather conditions, the driver has to keep the vehicle running. “And you have to find a way to move the vehicle physically as best you can because you are going to need the duty cycle on the vehicle to get the temperatures that you need for the regeneration process.”