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Diesel Quality

The recent unprecedented escalation in fuel prices has placed tremendous pressure on transporters and other intensive diesel users in the country. Fuel costs now account for 55% – 60% of a transporters cost base, and escalating diesel costs have significantly reduced available cash flow in transport businesses. It therefore stands to reason that purchasing fuel at competitive prices has now become imperative for the survival of any business that uses a significant volume of fuel. This pressure to source cheaper fuel has unfortunately led to the proliferation of unscrupulous fuel suppliers (commonly known as spikers) who adulterate (or “spike”) diesel with cheaper, lower specification petroleum products such as:

  • illuminating paraffin (IP)/kerosene; and/or
  • used engine oil; and/or
  • Jet A1; and/or
  • burner fuels such as Fuel Oil Light (FOL)

The above products are added to standard diesel by the spikers, thus diluting or spiking the diesel, in order to lower the base cost of their “diesel”, thus allowing them to sell their “diesel” cheaper than the ruling market rate.

In previous communications, the regulated price buildup of diesel was explained, including the current tax regime that is applied to each litre of diesel supplied within South Africa. Taxes and duties on diesel is currently R5.05 per litre, and will escalate by a further R1.50 in August 2022 when the current tax relief measures come to an end.  These taxes and duties are not applicable to the above-mentioned products. Therefore, for every litre the diesel that these unscrupulous spikers substitute with the above listed products, they gain the duties and levies as additional margin. They are then able to cut prices significantly on this spiked “diesel” due to this additional margin.

However, the downside to the end-user of this cheaper “diesel” is significant. While they may have purchased “diesel” at a significantly cheaper price, the poor quality of this product will lead to damage to their vehicles and/or equipment, particularly the fuel pump and injectors.  The costs of repairing injectors and pumps, especially in the modern high pressure fuel injection systems, is significantly higher than any savings achieved from using the cheaper “diesel”.

Diesel quality is governed by the SANS 342 specification in South Africa.  All diesel that’s refined, imported, or supplied out of the major oil companies has undergone stringent testing and quality control, and will conform to this specification. Illuminating paraffin (IP) is the predominant petroleum product used to spike diesel with, since its chemical properties are very similar to that of diesel, and since diesel engines can run on pure IP for a short time (albeit until the injector pump and injectors are damaged to the point where they are not able to function). IP also does not attract the taxes and levies that diesel does. To combat spiking and prevent a loss of the taxes and duties to the fiscus, the Government has introduced the Authentix A1 marker into IP. If threshold traces of the Authentix A1 marker is detected in any diesel tested, it would indicate that the tested fuel has been spiked with IP.

Testing of fuel differs in sophistication, ranging from a simple field test, using the Authentix “pregnancy-test” type kits; to more sophisticated lab analysis through companies such as Wearcheck and Mobilab; to specific test for the Authentix A1 tracer at labs such as SGS.

Unfortunately, the huge sums of money involved, and the excessive margins being generated by the spikers has resulted in some of them setting up their own labs and refining the “spiking” process to the point where they are able to mask/circumvent the pregnancy-type field tests.  The only other way to reliably check diesel quality is to do a lab analysis through a company such as Mobilab or SGS.

Depending on the ratio of IP to diesel (mix ratio), the various parameters measured by the labs will be affected differently and will deviate from the industry standard as stipulated in the SANS 342 specification.

Herewith some examples of actual Mobilab test results of diesel spiked with different contaminants:

Illuminating Paraffin / Kerosene:

TEST DESCRIPTIONTEST METHODSPECIFICATION: SANS 342, 2016
Sample Point>
TEST RESULT
##XXX
AppearanceASTM D4176Bright & Clear, No Free Water, No suspended particles or sediment✅ Bright and clear
#ColourVisualYellow / Greenish Yellow✅ Light Greenish Yellow
Haze TestASTM D41762 max.1
Density @ 20deg. C, kg/m³ASTM D4052800 min.✅ 807.0
Flash point, deg. CASTM D93 (A)55 min.red diamonds square 52.6
Water content, mg.kg (ppm)ASTM D6304350 max. ✅ 69.6
#Distillation: 90% Recovered, deg. CASTM D7345362 max.✅ 324
#Sulphur content, mg/kg (ppm)ASTM D545350 max.✅ 13.7
#Viscosity @ 40 deg. C, cStASTM D70422.0 – 5.3red diamonds square 1.8
#A1 Market TestFD TestNegativered diamonds square Positive
TEST RESULT STATUS:
✅ (Pass) Results comply to the requirements of SANS 342:2016 for diesel.
red diamonds square (Fail) Results do not comply to the requirements of SANS 342:2016 for diesel.
⚠️ The specification falls within the uncertainty of measurement range of the result, and the decision on statement of conformity (Pass of Fail) lies within the responsibility of the customer.

The tested parameters that are typically adversely affected by JetA1/FOL contamination are:

  • Density: while not indicated in the above test results, significantly high IP content will result in the density of the tested product dropping below the minimum level of 800 kg/m3.
  • Flashpoint: IP contamination will result in the flash point dropping below the minimum level of 550C. In high compression diesel engines this may cause pre-ignition in the cylinders, leading to massively increased engine stress.
  • Viscosity: IP content will drop the viscosity below the minimum level of 2.0 cSt at 400C. This decreased viscosity will result in a lack of lubrication, and therefore excessive wear in both diesel injector pumps and injectors.
  • A1 Marker:If the tested fuel has not been treated by the spikers to mask the presence of Authentix A1 marker, this test will indicate the presence of the marker and therefore IP in the tested diesel. However, the actual percentage contamination cannot be determined with this type of test. When subjected to the relevant SGS test, the exact percentage of contamination can be determined.

Jet A1 / Fuel Oil Light (FOL):

TEST DESCRIPTIONTEST METHODSPECIFICATION: SANS 342, 2016
Sample Point>
TEST RESULT
##XXX
AppearanceASTM D4176Bright & Clear, No Free Water, No suspended particles or sediment ✅ Bright and clear
#ColourVisualYellow / Greenish Yellow✅ Water White with Tinge of Yellow
Haze TestASTM D41762 max.✅ 1
Density @ 20deg. C, kg/m³ASTM D4052800 min.✅ 811.4
Flash point, deg. CASTM D93 (A)55 min.red diamonds square53.6
Water content, mg.kg (ppm)ASTM D6304350 max. ✅ 40.9
#Distillation: 90% Recovered, deg. CASTM D7345362 max.✅ 256
#Sulphur content, mg/kg (ppm)ASTM D545350 max.red diamonds square712.1
#Viscosity @ 40 deg. C, cStASTM D70422.0 – 5.3red diamons square1.5
#A1 Market TestFD TestNegative✅ Negative
TEST RESULT STATUS:
✅ (Pass) Results comply to the requirements of SANS 342:2016 for diesel.
red diamons square (Fail) Results do not comply to the requirements of SANS 342:2016 for diesel.
⚠️ The specification falls within the uncertainty of measurement range of the result, and the decision on statement of conformity (Pass of Fail) lies within the responsibility of the customer.

The tested parameters that are typically adversely affected by JetA1/FOL contamination are:

  • Density: while not indicated in the above test results, significantly quantities of FOL may lead to increased density, to above the threshold level of 850 kg/m³; similarily significant quantities of JetA1 may lead to decreases in density to below the threshold level of 800 kg/m³.
  • Flashpoint: Jet A1/FOL contamination will result in the flash point dropping below the minimum level of 550C. In high compression diesel engines this may cause pre-ignition in the cylinders, leading to massively increased engine stress.
  • Viscosity: JetA1/FOL content will drop the viscosity below the minimum level of 2.0 cSt at 40℃. This decreased viscosity will result in a lack of lubrication, and therefore excessive wear in both diesel injector pumps and injectors.
  • Sulphur Content: Both JetA1 and FOL have very high sulphur content, which will result in the contaminated diesels sulphur levels exceeding the maximum of 50ppm. High sulphur content leads to the formation of sulphuric acid during the combustion process, which has a negative effect on engine components, especially seals and bearings.
  • A1 Marker: As both JetA1 and FOL are not treated with Authentix A1 marker, this reading with indicate a negative status.

Spiking has proliferated in industry to a point where it is severely impacting the viability of legitimate fuel wholesale businesses that do not trade with spike fuel. The unfortunate result is that some well-known fuel suppliers have now begun to spike in order to compete and survive economically.

While it is tempting to purchase cheap “diesel” due to the perceived economic benefits, it is an unfortunate fact that this cheap product results in more damage than benefits accruing to the end user.

It is important to determine that the diesel you purchase is sources from a major oil company depot, as you can then take some comfort that it will meet the SANS 342 specification. Given the escalating cost of vehicles and their maintenance, it is wise to test your fuel on a regular basis if not sourced directly from a major oil company’s supply facility, to ensure that you are running your vehicles on quality product.

Contact numbers of reputable testing labs listed below

Mobilab: 082 899 0601 | SGS: 031 466 2713

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