Reading time: 6 min
09.01.2023
author Ing. Ladislav Fuka, Fuel expert

Fuel Quality – Basic Requirements

It follows from market research all around Europe that along the price, the most important factor in a customer’s decision-making process, including where to buy fuel, is the perception of fuel quality.

Fuel Quality – Basic Requirements

How to Recognize Good Fuel:

One on hand everyone surely wants to buy goods of the highest affordable standard. On the other hand, once we stop at a filling station, open the tank cap, insert the nozzle, and press the lever, do we have any chance to judge the quality of the fuel flowing into our tanks? The answer is no, we don’t. We can’t see the fuel and even if we could, we can’t differentiate quality levels on eyesight alone. We can get certain impressions from the station’s surroundings, tidiness and availability, and the quality of other services that are not related to the fuel itself. For the true proof of quality, we must go deeper and be attentive to what the fuel supplier claims they are doing, and what kind of evidence they are offering to show us the validity of their product. To rightfully assess whether the fuel is high or low quality, we need to understand what fuel quality truly is and be aware that there is more than one quality level.

Basic Requirements of Premium Fuel Properties

The first requirement of quality fuel that most of us have surely heard about is the conformity with the basic international fuel quality standards. For Diesel fuel in the EU, EN 590 is the obligatory norm. It seems to be quite straightforward, the fuel either meets the standard or it does not, but the norm is comprised of 18 different parameters and most of them, if not all, should be observed to exhaustively evaluate the quality. These parameters also include limits that must be fulfilled. If any discrepancy in a random parameter is found, the fuel is automatically incompliant and based on the degree of violation, the fuel can be seen as potentially harmful for vehicles’ condition or for the surrounding environment. It may even be the product of fraudulent activities. On the other hand, the discovery of a discrepancy on a smaller scale does not automatically mean there is a serious threat. To better understand the seriousness of parameter violations, let’s divide the cases into groups. 

Seasonal Quality Violations

The most important seasonal parameter of Diesel quality is its low temperature flow properties. If the fuel fails to pass the filterability test, CFPP (Cold Filter Plugging Point), and the ambient temperatures are low enough, the vehicles’ operability may be compromised as fuel filters tend to get clogged with solidified matter more quickly. Such quality violations are considered to be unintentional, and the fuel causes no further damage. The fuel supplier likely has just not managed to switch to a more freeze-resistant fuel in time. It rarely happens even to the most renowned companies, but only at the beginning of the winter season. If an instance like this is discovered by a national surveillance body, the company is usually moderately penalized. 

Poor Fuel Management and Handling

The most commonly violated parameter for the category of Diesel fuel is the flash point (FP). The flash point is a safety measurement, and Diesel fuel is considered a Group III flammable substance and is required to have a flash point above 55°C. If the flash point is found to be lower, the fuel is no longer considered to be in this category and stricter safety precautions should be taken. While this may not seem important to the end customer, it can pose a significant risk. The main reason why the FP drops is the presence of gasoline as the most dominant contaminant in Diesel fuel. There are certain documented cases when such contaminated fuel has caused a fire in the vehicle’s aftertreatment system, but the main threat dwells in fuel dilution and viscosity drop. In other words, Diesel fuel strongly contaminated with gasoline creates a much thinner lubrication film in many susceptible-to-wear fuel system parts, like fuel pumps and injectors. Such fuel may cause irreversible damage whose manifestation may be deferred (even during months of operation). 

Consequences of Bad Fuel Quality

The penalization of a quality breach depends on its severity. Flash points ranging down to 45°C tend to be fined moderately because they do not pose an excessive risk to vehicles. On the contrary, flash points below 20°C are very serious and so are the consequences. The flash point discrepancies are not, in the majority of cases, to be blamed on the filling stations themselves. They may result from poor gasoline vapour recovery system design or other technological defects, but most of the time, it is the fuel supply chain and tanker trucks that are at fault. The problem is quite simple – the Diesel fuel is being shipped in a tank chamber that previously contained gasoline, or the truck operator discharged gasoline into a Diesel tank by mistake. Human factor is of great importance here and any attempt to cover up the error (e.g., trying to balance out the quantity of each fuel with reciprocal discharging of Diesel fuel into the gasoline tank) can cause an enormous headache. 

Select Trustworthy Fuel Suppliers

The last group of quality inconsistencies are related to fuel production. Errors in official production made by refineries and fuel terminals happen, but they are very rare. If something like this occurs and the output quality control fails to detect it, those violations are often less serious, and are limited to minor deviations, e.g., in sulfur or FAME (biodiesel) content, distillation curve or cetane number.  

However, there is a special group of the most contemptible production quality defects that arise from fraudulent activities, and they are the direct results of fuel adulteration. The technique behind fuel adulteration is to admix cheaper components with those that are already present in the fuel. The lower price may be achieved through lower, or even the absence of, taxes imposed on admixed matter, or previously used matter that is considered to be waste or a secondary resource. The most frequently misused hydrocarbon fractions are solvents and industrial operation fluids, like lubrication, and forming and transformer oils. Such products generally exceed the boiling range of Diesel fuel (being heavier than that), they have a higher sulfur content, or they contain other contaminants that are very dangerous to engines and aftertreatment systems. Such adulterated fuel is difficult to combust, leaves carbonization residues (like soot), and harms the overall condition of the powertrain through excessive deposits. Excessive sulfur content or any other acid forming substances may also significantly damage the engine, creating a corrosive environment and depleting the protective additives in engine oil. Such a finding in fuel quality testing must not be found at any reputable filling station, and if it is, a massive financial penalty is the smallest problem they face, because the damage to their reputation can be even more devastating. If you’re looking for a trustworthy fuel supplier, have a look at the Eurowag Fuel Offer, which includes both classic and alternative fuels.

EU requirements

As indicated before, filling stations all over the EU are subject to regular quality surveys conducted by each state government. However, the fundamental EU requirements are quite low in overall intensity, and it is up to national consumer protection agencies to make them more stringent. In addition to the general reputation and quality impression, if any filling station chains want to show additional care regarding their fuel quality, it is the best to conduct independent, third-party fuel quality monitoring, i.e., regular fuel sampling and analysing without any advanced notice. These are the ones that really deserve our trust because they do not hide anything from their customers. Eurowag offers an easy solution for truck driving companies to pay and find high quality fuel stations with the Eurowag fuel cards that are valid all over Europe.