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28/07/2023 News

Oil challenges

The era of the classic, internal combustion engine is slowly coming to an end. However, if anyone thinks that the engineers responsible for developing new engine oils can slowly start looking for another job, they are mistaken. TotalEnergies' Technical Department Manager Andrzej Husiatyński points out that today's green engines are more demanding than older designs and require increasingly sophisticated oils.

The era of “downsizing” internal combustion engines has arrived. The process of “downsizing” describes the tendency of automotive designers to use drive units with ever smaller displacement, but which achieve significantly higher torque and power values at the crankshaft. How is this possible? All thanks to the use of a suitable turbocharging system and electronically controlled multi-phase fuel injection. This means that a large amount of cooled air enters the combustion chamber and fuel injection is split into several phases. This ensures optimum mixing of the fuel-air mixture, i.e. full utilisation of a given engine volume. As a result, we are able to obtain significantly better performance from engines with a relatively small capacity. Like any technical solution, this also has its disadvantages. They can be minimised by using the latest oils from the Quartz range such as:

QUARTZ 9000 FUTURE FGC 5W-30,
QUARTZ INEO EcoB 5W-20,
QUARTZ INEO Xtra EC6 0W-20
.

"Many drivers and mechanics believe that the driving force behind oil sales is purely marketing. What's more, there are cases where the purchaser doesn't pay much attention to the specifications and chooses whatever oil is currently on promotion. Unfortunately, this is a mistake that drastically reduces the life of the engine. The requirements of engine builders are legitimate and some specific characteristics of individual oils are facts." TotalEnergies Technical Department Manager Andrzej Husiatyński.

Soot dispersion capacity

Until now, particulate emissions have not been an environmental problem in spark-ignition engines as they are in compression-ignition engines. Petrol has a lower propensity to form soot than diesel. However, the process of downsizing has led to the fact that, in petrol engines, at high loads, excess fuel spaces are created in the combustion chamber, which at high temperatures causes their particles to break down thus producing unburned carbon in the form of soot. It is for this reason that the latest petrol engines are fitted with petrol particulate filters (GPF). This situation has therefore created a new challenge for engine oils, which must have a much higher soot dispersion capacity. Soot from the combustion chamber also enters the oil, and the oil must absorb it, transport it towards the filter and reduce the concentration of contaminants in the oil passages and within the timing chain (applicable to engines with chain). Soot has an abrasive effect on the chain pins causing chain elongation. The latest oils in the Quartz range “take care” of the chain by protecting it from soot.

Reduction of the LSPI phenomenon

The LSPI (Low Speed Pre-Ignition) phenomenon, the occurrence of glow ignition at low speeds, is the biggest problem in downsizing petrol engines. Glow ignition results from the appearance of an additional ignition source in the form of any hot spot in the combustion chamber. Glow ignition occurs at one or several places inside the combustion chamber simultaneously. There are several reasons for this phenomenon. Unburned fuel dissolved in the oil film, contamination of the combustion chamber with carbon build-up or glowing oil particles or burning soot particles. Glow ignition leads to very high mechanical stress on the crank system and a loss of engine power. Often the consequence of glow ignition is knocking combustion. The latest oils of the Quartz range, with their composition, reduce the number of glowing oil particles and ensure clean combustion chamber. In this way, they reduce the propensity for the LSPI phenomenon. The LSPI phenomenon is also influenced by the engine speed. As it increases, the turbulence of the air-fuel mixture increases, which promotes an increased combustion rate. This results in a lower propensity for the phenomenon of glow ignition, due to the rapid burning of residual impurities in the chamber. Therefore, when using a downsizing engine, avoid driving at low speeds. It is always better to drive in a lower gear than to expose the engine to the LSPI phenomenon.

Improving engine efficiency

The friction between moving engine components depends on the oil film. The lower the friction, the greater the efficiency and the lower the fuel consumption. The latest oils in the Quartz range have low viscosities (0W-20 and 0W-16) and anti-wear additives to protect the most stressed engine components. One indicator of oil quality in this regard is the European ACEA standard. Oils in the Quartz range, meeting ACEA C5 and C6 standards, are significantly better in terms of reducing internal resistance. Remember that you should always be guided not only by the viscosity but also by the standard indicated in the owner's manual of the respective car.

Limitation of ash content

The latest internal combustion engines have to comply with standards for reducing exhaust emissions. For this reason, oils must be specially adapted to engines with exhaust aftertreatment systems. Regardless of whether a car is one year old or 10 years old, if it is fitted with a particulate filter, it must run on LowSAPS (low ash) oil. The use of any other, cheaper oil leads to the destruction of the filter by irreversibly clogging its porous structure with impossible-to-remove sulphate ash formed by the combustion of oil particles that enter from the combustion chambers. Quartz oils from the INEO range, with ACEA C standards, contain low ash additives to prolong the life of exhaust after-treatment system components.

"The TotalEnergies range includes older oils meeting one of the conditions described here. But there are also state-of-the-art products that meet all of them at the same time. And this is pretty much the only sensible room for manoeuvre for someone buying oil for their car. As you can see, all the key oil requirements, have their rational basis, and neglecting them can have a direct, negative impact on engine performance or visibly (sometimes surprisingly) accelerate its wear and tear." TotalEnergies Technical Department Manager Andrzej Husiatyński.