LongLife cycle between oil changes - almost every driver has come across this term. It refers to the extended service intervals recommended by most automakers. The justification for such a policy is environmental and economic. The planet benefits, because less frequent maintenance means less oil to dispose of. It's also good for the wallet, since inspections are paid for and thanks to the fact that fewer of them fall out per year, servicing costs are also lower.
Unfortunately, engines, specifically their durability, may lose out on all this. Someone may ask at this point - how is this possible, when oils adapted to such a service mode are now offered? Yes, but the LongLife mode does not usually distinguish the specifics of operation. In more expensive cars, the oil change date can be accelerated by the on-board computer, which will display an appropriate message on the dashboard. In cheaper cars - there is no such option in the menu. In this situation, drivers use the vehicle according to its instructions regardless of where and how they drive. They adhere to the oil change interval every 30,000 km, for example, without much thought to the engine's operating conditions.
The automatic selection of LongLife mode when determining the service schedule is most often based on statistics. The model driver drives according to regulations, in a mixed cycle with a light vehicle load. And indeed - making such assumptions, the LongLife mode may prove to be as sufficient as possible. What's more - it is possible to imagine such operating conditions in which the service interval could be extended even further. Daily driving on a flat suburban road for more than 20 km, without traffic lights at intersections, with little traffic, in the speed range from 80 to 90 km/h. In addition, a moderate climate, temperatures of 15-20 degrees Celsius and no rainfall. That is, operating conditions corresponding to the lowest load on the engine and its lowest combustion.
The problem is that few drivers travel this way. Therefore, intervals between oil changes should be adjusted individually. Of course, you can't extend them indefinitely, but shortening them, regardless of factory recommendations, will be most justified.
In cars equipped with an extensive self-diagnostic system, it happens that the on-board computer displays a message ordering an oil change ahead of schedule. This is usually not due to diagnostics of the degree of oil contamination by measuring electrical resistance. And the higher the combustion and more difficult operating conditions, the higher the oil contamination and oxidation. Vehicles are fitted with systems in which a computer analyzes the way the vehicle is operated (engine speed, accelerator pedal pressure, braking and acceleration cycles, temperature, etc.) and, based on this, calculates the estimated time until the next oil change. It therefore does exactly what a car driver without such equipment should do. It takes into account the driving style and operating conditions of the vehicle. If everything runs smoothly - the LongLife cycle is unlikely to do any harm. When the car is loaded - the interval should be shortened.
City driving
Short motoring, frequent intense acceleration, driving on an underheated engine - these are the main factors that undoubtedly suggest a faster than usual oil change. Prolonged travel with a cold engine is just as damaging to the oil as driving in its upper temperature range. There are other dangers to consider in this situation. A greater risk of fuel contamination of the oil, accumulating moisture in the lubrication system, repeated and intermittent cleaning procedures for the diesel particulate filter - all of these tend to shorten oil change intervals. In addition, frequent starting and accelerating increases combustion, which means more contamination in the oil.
Highway driving
In advertisements - so-called highway mileage is signaled as an advantage. Unfortunately - it is beneficial for the engine only if the driver follows the rules and does not overload the car. Meanwhile, driving too fast, hot weather, a trailer or a set of passengers can drastically change the conditions for such operation. If the engine burns much more fuel while driving on a highway than in normal off-road driving, it means more pollution. Driving with a heavy load on the drive unit raises the temperature of the oil, which accelerates its oxidation - aging. Definitely - regular highway driving requires shorter oil intervals.
Engine wear
With age and mileage, the engine loses its performance and requires more frequent oil changes. This includes the fact that wear and tear on the fuel supply and intake system can contaminate the oil with fuel, soot, or moisture. Older engines with high mileage do not “hold” compression which worsens the combustion process and can cause more exhaust gas blow-by into the crankcase. This drastically shortens the life of the oil. Sometimes this accelerated replacement is even necessary. The oil is more contaminated and can be diluted with fuel from a faulty combustion process.
Clogged DPF
When the DPF is already heavily clogged with ash, there is a reduction in its capacity. The key is the amount of soot it can accept to burn off. More frequent forced “regeneration” of the DPF occurs, and this can mean an increase in the amount of fuel in the oil. In drastic cases, the oil level rises above the maximum level on the dipstick. This means that the lubricating properties of the oil deteriorate and the oil needs to be changed more often.
Low annual mileage
People who drive little should also opt for shorter intervals between oil changes. Lubrication also wears out from the sheer passage of time. If someone drives 3,000 kilometers a year, for example, he should change the oil once a year, although of course he doesn't have to stick strictly to the calendar. A few months difference between oil changes in this particular case is rather safe for the engine.
Tuning
Due to the fact that an increasing number of cars are factory-equipped with turbochargers, electronic tuning is growing in popularity. It can be said that these days it is becoming available at your fingertips. You don't even need to visit a workshop - modules introducing changes in the engine control software can even be ordered over the Internet, and plugging them into the vehicle's computer is usually trivial.
Any modification of engine parameters and especially power changes the operating rules. More power means more serious thermal stress on the engine and oil, i.e. its oxidation. In addition, poor quality tuning often means giving excess fuel when accelerating. These are arguments for shortening the interval between oil changes.
Black color says little
Many drivers try to judge the condition of oil by its appearance. Black color indicates wear and tear, amber color - suggests that it is still in perfect condition. Unfortunately, this approach is wrong.
Oil can wear out in two ways - chemically (it loses properties) and physically (for example, it is contaminated). However, it should be noted that some oils are designed to absorb as much contamination as possible and not allow these contaminants to settle inside the engine.
An excellent example of this is TotalEnergies oils with strong soot dispersing properties. In fact, after just a few tens of kilometers, they can already turn black because they leach and bind soot without losing their lubricating properties. Of course, they can't accumulate this soot indefinitely, but a change in their color doesn't indicate anything yet.
In the TotalEnergies range, oils developed with ART (Age Resistance Technology) boast the best absorption properties. This is an advanced, ultra-modern formula that provides excellent antioxidant and antiwear properties to the engine oil. Throughout their lifetime, these oils can effectively absorb contaminants and protect the engine from their deposition.
Cleanliness can also mislead
Oil can wear chemically without losing its nice, original color. For example - in cars running on LPG, the oil remains clear for a very long time, because LPG burns very cleanly. However, chemical impurities appear in such oil, invisible to the naked eye, which deteriorate the lubricating properties.
This is, of course, the sulfur with which LPG is contaminated. This sulfur in the combustion process causes the formation of acidic compounds that penetrate the oil, acidifying it. Oil has some ability to neutralize these compounds, however, we advise owners of cars with LPG installation to very strictly observe oil change intervals, or even reduce them by half.
It's not just about lubrication
Many drivers associate oil wear only with deterioration of lubrication properties. Meanwhile, modern oils have other tasks. Chemical degradation means they can no longer perform them.
Among the most important “additional” functions of oil that disappear due to chemical wear are:
- protection of the engine against knocking combustion
- protection of timing chains from link wear and elongation
- maintenance of timing belts running in oil.
How often to change oil?
If the specifics of operation deviate from the ideal conditions mentioned at the beginning of the material, it will be reasonable to reduce the interval between oil changes by at least 1/3 of the recommended mileage. It used to be accepted that oil in diesels should be changed more often than in gasoline models, but nowadays, for design reasons, gasoline engines are becoming equally demanding.