</font><font color="blue" class="small">( My BX is a bear to start in the single digets whats this treatment you mention? Brad )</font>
Invest in a block heater and your BX will start no matter what the temperature. The fuel treatments are for diesel fuel gelling, which is the separation of the wax in the diesel fuel from the other components. When this happens, the wax cannot get through the small passages and the fuel doesn't get to the injectors. With a good fuel treatment, you will get the engine running easier, but it still will need a longer warming period than if you have a block heater. The block heater will be the single best $35 investment that you will ever make in that tractor. When a engine block is very cold, there can be ice crystals that form in the combustion chamber that will prevent the engine from starting. With a warm engine block, you don't have this problem. As an experiment, take a piece of steel that has been outside and put it on the kitchen counter (wife allowing) and then pick it up an hour later. You will be surprised at how it holds the cold even when it is in a warm environment.