If change means progress, we are making a lot of progress! Fortunately our Pro-Ma DT5 plus concentrated diesel treatment continues to keep pace with progress!
About ten years ago our diesel fuel specifications were very different from what they are today.
Our diesel fuel contained much higher levels of sulphur, ranging from 0.5% to as high as 2.5% by weight.
Most of our diesel fuel originated from the bass strait oil field and contained a relatively high wax component.
Australia was divided into five regional zones for basic cloud point and cold filter plugging point limit zones.
The minimum automotive diesel fuel cetane rating was 40.
Most of the other component specifications have remained relatively static.
The Australian standard for automotive diesel fuel originated as AS3570-1988 and the second edition, AS3570-1998 replaced the original. This standard applies to fuel for high speed diesel engines, which operate above 800RPM. During February 1999 the ash percentage by mass was reduced from 0.1% to 0.01%.
Under the above standard, Australia is now divided into 12 zones and the maximum limits for cloud point vary for each zone for almost every month of the calendar year.
The cloud point is the temperature at which the wax crystals in the diesel fuel commence to form and become visible as a whitish cloud.
The cold filter plug point is the temperature at which these wax crystals agglomerate sufficiently to plug the fuel filter. The temperature difference between the cloud point and the cold filter plug point will vary with different batches of fuel and different climatic zones.
In some areas kerosene or heating oil are mixed with diesel fuel to improve cold weather starting. Caution is advised with these actions, as this could affect fuel viscosity, wear rates and contravene storage regulations.
The Commonwealth Government has introduced another specification, the fuel standard diesel determination 2001, which commenced on 1 January 2002.
Sections of this determination that are of special interest to us that the sulphur content must not exceed 500mg/kg from December 2002 and 50mg/kg from 1 January 2006. I have written a number of articles in recent years covering the result of the reduction of sulphur content in diesel fuel. Please refer to these for further information.
Another requirement from this determination is that from 1 January 2002 the cetane index of diesel fuel must be at least 46. In recent times this index has been as low as 40.
The cetane number in diesel fuel is a measure of its ignition quality. As with the octane rating of petrol, the test fuel is compared with a combination of two reference fuels that give the same ignition quality and anti knock rating.
If the cetane number is too low, the delay between injection and ignition is longer, white smoke on start up may become apparent in cold weather and ignition knock becomes more apparent. Prolonged use of low cetane diesel fuel can result in severe engine damage. Conversely, high cetane index fuels result in easier starting in cold weather, reduced white exhaust smoke and reduced diesel knock.
As a point of interest, the cetane index for the diesel fuel used in the T.A.F.E. report test was 52.
Some of the specifications above have been obtained from the Australian standard AS3570-1998 and from the Fuel standard diesel determination 2001. Additional information can be obtained, if desired, from this literature.
To obtain the best results from your diesel fuel, it is important that you protect it from climate extremes, under cover if possible. Ensure your fuel supply is fresh and is the appropriate summer or winter blend.
Changeover dates at the refineries are mid March and mid September, so allow for transport times to your area and avoid long term storage, as fuel deteriorates rapidly.
Use Pro-Ma Diesel treatment at the recommended dosage at each fill to help control fuel and combustion deposits, condensation accumulations, lubricate injection pump and injectors, improve combustion, reduce exhaust emissions and minimize cold flow problems. Its benefits far exceed its cost.