Towing a trailer and the condition of oil in an automatic transmission

It should be noted at the outset that this material is about large caravans with which we travel to the other end of Poland or even Europe. Light cargo trailers rented from construction stores usually do not pose any challenge to the car, especially when it comes to the occasional delivery of goods from the store to your home or allotment.The problem highlighted by TotalEnergies arises when the weight of the trailer approaches the upper limits of the car's capabilities, and the driver has hundreds of kilometers to cover, including mountainous routes. An additional challenge will be the high air temperature.

Different types, different requirements

There are many types of transmissions which we popularly call automatic. Each has different operating requirements and tolerates the additional load associated with towing a trailer in different ways. However, it can be said that in any case—if technically possible—an additional oil change before (or just after) a difficult holiday trip will not hurt. In the case of some types of transmissions, it is even recommended. Such a recommendation arises from the fact that automatic transmissions tend to overheat when towing heavy trailers. They also cause the cooperating elements to wear out faster. The oil interacting with the friction plates heats up locally and temporarily to extreme temperatures. These factors negatively affect the oil, changing its chemical and frictional properties and contaminating it. And that's why TotalEnergies recommends changing the oil.

You can often hear and see that the transmission is „getting tired”

A lot depends on the type of transmission and control electronics. For example, take a classic automatic transmission with a converter. If it is an older generation automatic or a newer one without proper synchronization with the trailer, then signs of „transmission fatigue” will be more frequent than usual, often accompanied by „pointless” gear changes. The driver may notice that the transmission has clear problems selecting the right range, causing it to „nervously” shift gears higher and lower as if it couldn't find the right gear. Sometimes the solution is to limit the gear range by one or two (many users forget that they have such a function in their car). If the newer transmission has electronic communication with the trailer—detecting its presence—the transmission usually changes gears a little later and keeps the engine at higher revs. In both cases, however, the driver may notice that the transmission is „getting tired.”

Automated transmission wear

Automated transmissions are actually manual transmissions with an added robot that controls gear shifting and clutch operation. They wear out during towing a trailer in the same way as ordinary manual transmissions, and in this case, oil degradation does not accelerate too quickly. Even if the clutch burns out during the trip, it does not affect the condition of the oil. TotalEnergies offers modern oils for this type of transmission with a relatively low viscosity (e.g., 75W), providing low dynamic resistance, excellent cooling, and special additives to protect the synchronizers. These oils also have high heat resistance (up to 180°C). An example of this type of oil is TRANSMISSION GEAR 9 FE 75W.

ZWear of classic automatic transmissions

In these transmissions, there is no mechanical connection between the engine and the transmission (except for the LockUp). An oil-filled converter is responsible for transmitting the torque. The oil is also found in the planetary gear unit that implements the ratios of individual gears, cooperating with multi-plate clutches. In these types of transmissions, the oil is particularly exposed to temperature increases and mechanical contamination. The oils used in such transmissions are highly advanced because they must have appropriate friction modifiers to provide a high coefficient of dynamic friction for quick gear changes and a high coefficient of static friction to avoid slipping. TotalEnergies oils in this class have low viscosity, adequate friction and strength parameters, good anti-wear properties, and special EP additives that react with the surface of metals. An example of oil for the latest types of automatic machines is FLUIDMATIC DVI MV.

This is one of the most technologically advanced options in its class, designed for the latest transmissions. It is used, among others, in AISIN WARNER: AW-2 (AISIN AT8) transmissions, which are found in many vehicle brands worldwide (mainly from the Stellantis group). This oil can also be successfully used in transmissions produced by ZF P/C 6HP / 8HP / 9HP family. It is also ideal for transmissions where DEXRON VI, MARCON LV, JASO M315, etc., are specified.

Wear of continuously variable CVT transmissions

CVT (continuously variable transmissions) typically consist of a pair of bevel gears connected by a chain or special belt, providing an "infinite" number of gears. These gears are connected to the motor by a coupling or a wet multi-plate clutch. These transmissions do not tolerate high torques well and will try to keep the engine at high revs during towing. If they do not recognize the additional load and keep the engine in a low "economical" range, their wear will be significantly faster. TotalEnergies aims to protect the chain or belt and bevels. This oil provides excellent friction properties to minimize loss and slippage on the chain/belt and is compatible with a wide range of materials used in the production of chains, belts, and pulleys. TotalEnergies oil example: FLUIDMATIC CVT MV.

Wear of dual-clutch transmissions

Dual-clutch transmissions are structurally two mechanical transmissions enclosed in one housing. One transmission handles even gears and the other odd gears. The connection to the motor is made by two multi-plate clutches. In transmissions with wet clutches, these clutches work in oil and are slightly more durable. In transmissions with dry clutches, there is no oil in the clutch assembly. Oil change is necessary for wet clutches; negligence in this matter drastically reduces the life of clutches. TotalEnergies recommends changing the oil in dual-clutch transmissions with wet clutches every 60-80 thousand km.Journeys with a trailer, which expose the clutches to faster wear, are an additional factor that shortens the life of the oil due to the wear of special friction additives. TotalEnergies oils for wet clutch dual-clutch transmissions have optimal friction properties and protect synchronizers. An example of oil for dual-clutch transmissions with oil-based clutches is FLUIDMATIC DCT MV.