Sales of gasoline in the country are falling, but with diesel fuel, things are not so bad. The reasons include military needs and the slow but steady recovery of our country's economy. The number of diesel cars is also growing. The diesel fuel at Ukrainian gas stations passed the test conducted in winter with honor, but what will happen in summer, especially after the recent price increase? Specialists from the Institute of Consumer Expertise looked into the matter, investigating how things are currently going for "heavy" fuel at Ukrainian gas stations.
Test control
This time, experts decided to check not only the major players but also to pay attention to medium and small chains. Samples were taken from 10 chains: WOG (Mustang DT), ANP (Energy), KLO (DT Euro), OKKO (DT Euro), AMIC (DT Euro), TNK (DT Euro), LUXWEN (DP EURO), BRSM-Nafta (DT Euro), Marshall (DT Euro), and SunOil (DT Euro). Prices varied slightly, but discounters offered lower prices than the leaders. In the laboratory, all samples were tested for 5 parameters: cetane index, fractional composition, flash point in a closed crucible, sulfur content, and density. Let's say right away that all tested samples turned out to be "summer" types. But there were some surprises.
Cetane index
First, specialists calculated the cetane index of the tested samples.
Cetane index - this is the cetane number of the fuel before the use of cetane-improving additives. The general principle is the higher, the better. All test participants met the standard, with the largest margin demonstrated by WOG (Mustang DT) samples - 55.3 units, and LUXWEN (DP EURO) - 54.4 units. Such diesel fuel will result in lower fuel consumption and smoke.
Fractional composition
The fractional composition of diesel fuels is important for diesel engine operation. With an increase in the content of light fractions in diesel fuel, the critical ignition pressure of the working mixture increases, knocks appear in the cylinders, and crankcase oil is diluted. Too heavy fractions burn incompletely and increase carbon deposits in the combustion chamber. Also, the fractional composition of diesel fuel indirectly characterizes its volatility. Fuel with a lighter fractional composition evaporates more easily. For automotive diesel engines, the most satisfactory fuel consists of fractions boiling at temperatures of 200-360°C. The narrower the temperature range in which the fuel boils, the better the combustion process in the engine. According to this indicator, all participants had no problems, with approximately the same values. The narrowest range (65-85 degrees Celsius) is for LUXWEN diesel.
Flash point
The second significant indicator is the flash point in a closed crucible. It characterizes the ignition temperature of the fuel. In the event of an accident involving a car fueled with fuel with a low ignition temperature, the driver's safety in this case is very conditional. In addition, this indicator can indirectly show whether foreign components have entered the diesel fuel. The best result, 70 degrees with a standard of not lower than 55, is for WOG (Mustang DT) and OKKO (DT Euro) fuel. But for the fuel purchased at the Marshall chain, the value was far below the limit - 47°C.
Sulfur
The main "environmental" indicator of diesel fuel is sulfur content. Although sulfur combustion products hit not only the environment but also the engine. Sulfur is deadly for catalytic converters and particulate filters, and removing it from fuel is a rather difficult and expensive process. With a sulfur concentration in fuel of less than 10 mg/kg, a converter "mileage" of more than a hundred thousand kilometers is not a problem. For example, if it is 1000 mg/kg (five years ago this was considered good), it may stop working effectively after ten to fifteen refuelings: sulfur, interacting with the precious metals of the converter, multiplies their chemical activity to zero. According to Ukrainian standards, different sulfur content is allowed in different types of diesel fuel. For type II (corresponding to Euro-4) - no higher than 50 mg/kg, and in type I fuel (Euro-5) - no more than 10 mg/kg. This time, the results were generally pleasing, but there was a fly in the ointment. Except for one sample, all samples met the highest Euro-5 level! The record holder was the WOG (Mustang DT) sample (only 3 mg/kg!). And the Marshall (DT Euro) sample spoiled the picture - a significant 370 mg/kg.
Total
The conclusion is simple - the quality of diesel fuel at Ukrainian gas stations is very high. The main competition is no longer so much about quality as about additional services and customer loyalty. Experts plan to talk about this in future studies.
Dmitry Gordienko
