by After the crisis ‘quarantine’ drop, fuel prices at Ukrainian gas stations confidently crawled upwards. At the same time, regarding diesel fuel, there is still quite a significant variance reaching 5 UAH per liter. But will there be the same difference in fuel quality? Specialists from the Institute of Consumer Expertise have looked into the issue; they purchased the most expensive and cheapest samples of ‘heavy’ fuel at Ukrainian gas stations and sent them to a laboratory for research.
Test ControlThe market is not standing still – and competitive struggle leads to segmentation. Following the premium segment (OKKO, WOG), discounters appeared (BRSM-Nafta, Chipo, SunOil), and then super discounters (Avantage, Marshall), working on the edge of dumping.
Besides, networks targeting specific consumer groups are emerging. For example, the rapidly growing nationwide network Prime offers preferences to truckers – for this, network gas stations create parking lots with all the amenities for a comfortable stay, offer discounts, and sell AdBlue liquid for exhaust neutralization. This time experts selected samples of ordinary ‘Eurodiesel’ in 11 networks: WOG, Parallel, ANP, Klo, Prime, OKKO, AMIC, BRSM-Nafta, SunOil, Chipo, and Avantage. In the laboratory, all samples underwent testing on 5 parameters: cetane index, fractional composition, flash point in a closed crucible, sulfur content, and density. To say it right away, all the samples were found to be ‘summer’ ones.
But surprises were not avoided.Cetane IndexThe first thing specialists calculated was the cetane index of the test subjects. Cetane Index – is the cetane number of fuel before the use of cetane-raising additives. The general rule is – the higher, the better. Unfortunately, not all test participants met the standard. In the sample acquired at Avantage gas station, the cetane index was almost 5 units below the standard.
The largest reserve was shown by samples Prime– 52.6 units, Parallel – 52.5 units, and Klo – 51.9 units. On such diesel fuel, fuel consumption and smoke will be less.
Fractional CompositionThe fractional composition of diesel fuels is important for the diesel’s operation. With an increase in the light fractions in diesel fuel, the critical ignition pressure of the working mixture rises, knocks appear in the cylinders, and the crankcase oil thins. Too heavy fractions burn incompletely and increase carbon deposits in the combustion chamber. Also, the fractional composition of diesel fuel indirectly characterizes its evaporability.
Fuel with a lightened fractional composition evaporates more easily. For automotive diesels, the most satisfactory is fuel consisting of fractions boiling at temperatures of 200-360⁰ C. The narrower the temperature range in which the fuel boils, the better its combustion in the engine. By this parameter, all participants had no issues, values are approximately the same. The narrowest ranges were shown by ‘diesel’ Parallel and BRSM-Nafta.Flash PointThe second significant indicator is the flash point in a closed crucible.
It characterizes the fuel’s ignition temperature. In the event of an accident involving a vehicle refueled with low flash point fuel, the driver’s safety is fairly conditional. Besides, this indicator indirectly can show if foreign components entered the ‘diesel.’ The best results, 65 degrees at a standard not lower than 55, are from Parallel and Prime fuels. However, the fuel acquired in the Avantage network was well below the boundary – 37 C0.
SulfurFinally, the main ‘environmental’ indicator of diesel fuel is sulfur content. Although combustion products of sulfur hit not only the environment hard, but also the engine.
Sulfur is fatal for converters and particulate filters, removing it from fuel is quite a difficult and costly process. At a sulfur concentration in fuel of less than 10 mg/kg, a converter’s life of over hundreds of thousands of kilometers is not an issue. For example, if there are 1000 mg/kg (this was a norm just six or seven years ago), it may cease effectively working after ten to fifteen fillings: sulfur, interacting with precious metals of the converter, multiplies their chemical activity by zero. According to Ukrainian standards (similar to Euro 5), sulfur content in fuel is allowed up to 10 mg/kg. This time the results were generally satisfactory, but there was a fly in the ointment.
Except for one sample, all samples met Euro-5 level. Samples from Parallel and Prime were practically free from harmful sulfur (5 mg/kg). Just slightly short of the leader was the sample obtained at the Chipo gas station – 5.5 mg/kg. But the diesel sample from Avantage showed a significant 216 mg/kg, which is more than 20 times the limit.ConclusionThe research picture turned out to be ambiguous. On one hand, just one sample was non-compliant, which speaks of stability in supplies and a meticulous approach to logistics and entry control in serious networks.
Apparently, retailers are not keen to take on reputational risks and engage with ‘left’ fuel, especially during periods of spill declines. On the other hand, the quality in ‘medium’ networks has leveled and even surpassed the performances of their premium segment counterparts, while the price difference among them remains quite tangible so far. Is it necessary to pay more? However, each car owner is free to answer this question themselves. Nonetheless, motorists should still approach ‘super sweet’ offers on stells with great caution.
Dmitry Gordienko
