Common misconceptions customers have about "regular oil changes"

META DESCRIPTION

Changing the oil at the correct mileage is not necessarily the correct maintenance schedule. The lifespan of transmission fluid also depends on operating conditions, temperature, load, type of transmission, and the standard of oil used.

Changing the oil at the correct mileage doesn't necessarily mean changing it at the right time.

When it comes to car maintenance, many car owners often keep one simple principle in mind:

Change the oil at the specified mileage.

This tracking method helps prevent the oil from being used for too long. However, mileage is only one of many factors that determine when the oil needs to be checked or replaced.

Two cars that have both driven 40,000 km may have very different transmission fluid conditions.

A vehicle that regularly travels on highways at a stable speed and with a light load will have different working conditions than a vehicle that:

Traveling mainly within the city.

Frequent traffic jams

Heavy load

Run the service

Climbing hills or traveling on mountain passes.

Continuous operation in hot weather

Therefore, "changing the oil on schedule" should not be understood simply as changing it at the exact mileage indicated on the schedule.

A proper maintenance schedule should be based on mileage, usage time, and the vehicle's actual operating conditions. Gartz also notes that there is no single fixed number that works for every vehicle, as oil life is affected by transmission type, temperature, driving habits, and operating environment.

Misconception number one: As long as you haven't driven a kilometer, the oil is still good.

This is a very common understanding.

For example, a car owner plans to change the transmission fluid at 50,000 km. When the car has only driven 35,000 or 40,000 km, they often assume the fluid is still good.

However, the oil may degrade faster than expected if the vehicle is regularly operated under harsh conditions.

In Vietnam, vehicles often face the following challenges:

Prolonged traffic jam

Stop and start continuously

High ambient temperature

Short distance but long operating time

The gearbox must continuously shift gears at low speeds.

Under these conditions, the vehicle may not travel many kilometers, but the oil is still subjected to heat and pressure for many hours.

In other words, the odometer doesn't fully reflect the amount of work the oil has done.

As the oil begins to degrade, its viscosity, pressure transmission capacity, and friction characteristics may no longer be as stable as they were initially, even if the transmission hasn't yet shown any obvious faults.

Second misconception: All cars have the same oil change interval.

There is no single cycle that applies exactly to all vehicles.

The timing for checking and changing the oil also depends on:

Automatic transmission (AT), CVT, DCT, DSG, or manual transmission.

Manufacturer's design and requirements

Maintenance history

Regular load

Frequency of running in urban areas

Operating temperature

The actual condition of the gearbox

CVT transmissions have different friction control requirements between the belt and pulley compared to traditional AT transmissions. DCT transmissions, on the other hand, have specific requirements for the clutch assembly and control system.

Therefore, even with the same mileage, different types of transmissions may require different evaluation methods.

The important thing is not to find a single number that works for all cars, but to correctly identify the type of transmission and the specific operating conditions of that particular vehicle.

Refer to the Gartz transmission fluid catalog:
https://gartzlube.com/vi/dau-hop-so

Misconception number three: Changing the oil on time doesn't mean any oil will do.

A car may have its oil changed regularly but still experience problems if the product used is not up to standard.

Gear oil isn't just for lubrication. It's also directly involved in:

Hydraulic pressure transmission

Control the gear shifting process.

Control the coefficient of friction.

Cooling the internal components

Supports torque converter operation and lock-up.

Protect the valve body, solenoid, and clutches.

Each type of oil may differ in the following ways:

Viscosity

Friction properties

Heat resistance

Additive system

Technical standards

Compatible gearbox type

Therefore, changing the oil at the correct mileage but using the wrong viscosity or standard can still cause the gearbox to operate erratically.

The following vehicles may appear:

Turn into D or R slowly.

Shifting gears is not smooth.

Slight vibration when accelerating

The car reacts differently when it heats up.

The engine revs up but the power transmission is not seamless.

The right oil isn't necessarily the thickest, most common, or most expensive. The right oil is the one that meets the specific technical requirements of your vehicle's transmission.

See more technical articles:
https://gartzlube.com/vi/top-5-dieu-khach-hang-thuong-hieu-sai-ve-dau-hop-so-o-to

Misconception #4: A car that's driven infrequently can extend the oil change interval.

A car with low mileage doesn't necessarily mean it's been driven in light conditions.

A car that travels only a short distance each day, but frequently:

The engine has been running for a long time.

Traffic jam

Slow movement

Stop and accelerate repeatedly

The machine was shut off before reaching a stable temperature.

This can still cause the oil to bear a significant load.

In automatic transmission vehicles, each time a vehicle moves forward, stops, and then continues moving, the hydraulic system and clutches are required to operate.

Therefore, operating time and heat load are sometimes just as important as the number of kilometers driven.

For cars that are driven infrequently but mainly in urban areas, owners should still check the oil periodically instead of just waiting for the odometer to reach the correct mark.

Misconception number five: Just because the oil hasn't changed color or the car hasn't displayed any error codes doesn't mean it needs checking.

The color of the oil can aid in a preliminary assessment, but it is not the sole basis for concluding whether the oil is still good or not.

The oil may still retain its relatively normal color, but:

The viscosity has changed.

The additives have decreased.

Lower heat resistance

The friction characteristics are no longer stable.

Pressure control capabilities have decreased.

Similarly, the fact that the car hasn't displayed any error codes doesn't necessarily mean the transmission is operating in optimal condition.

In the early stages, car owners may only notice minor changes such as:

Shift gears more slowly.

There is a slight delay when shifting gears.

When the car heats up, it no longer runs smoothly.

Slight vibration when holding the throttle.

Throttle response is no longer seamless.

This is the time to have it checked, rather than continuing to use it until the transmission warning light comes on or a serious fault occurs.

"On schedule" must include operating under the correct conditions.

A proper maintenance schedule isn't just about the numbers on the odometer.

Vehicle owners should consider whether their vehicle is regularly operated under the following conditions:

Traffic jams and constant stop-and-go traffic.

The gearbox must constantly change states while its cooling capacity is limited.

Heavy transport or ride-hailing services

Heavy loads require the gearbox to transmit higher torque, generating more heat.

Frequent uphill climbing or mountain driving

The gearbox must shift gears, maintain pressure, and withstand loads for extended periods.

High ambient temperature

High temperatures force the oil to work under harsher conditions and can accelerate its degradation.

Traveling short distances but operating for long periods.

The car may accelerate slowly, but the total time the oil is exposed to heat is very long.

If a vehicle frequently falls into one of the above categories, the inspection cycle may need to be performed sooner than for vehicles that are primarily used for stable highway driving.

"Regularly" also means using the right type of oil.

Choosing transmission fluid should be based on at least four factors:

The right type of gearbox

Meets technical standards

Correct viscosity

Correct friction characteristics

Your choice shouldn't be based solely on:

Oil paint

Selling price

The belief is that the thicker the oil, the better.

The term "multipurpose oil"

Experience from another car model

AT, CVT, and DCT systems operate on different principles, so they cannot be interchangeably fitted with the same type of oil.

Even within the same AT group, 4-speed, 6-speed, and 8-9 speed transmissions may require different oil characteristics.

Modern transmissions operate with precisely controlled pressure, shift timing, and lock-up capabilities. Therefore, incorrect oil levels can significantly affect the driving feel compared to older transmissions.

Learn how to choose the right oil for each type of transmission:
https://gartzlube.com/vi/dau-hop-so-o-to-va-cach-chon-dung-theo-tung-loai-at-cvt-dct-mt

"Regular maintenance" must take heat load into account.

Temperature is one of the biggest factors affecting the lifespan of transmission fluid.

When working regularly in high temperatures:

Oil oxidizes more easily and quickly.

Viscosity decreases steadily.

The ability to control friction is impaired.

Loss protection additive

Dirt and grime form easily.

The internal components are subject to more wear and tear.

Especially in urban traffic conditions, the gearbox can generate heat continuously but does not receive the same cooling airflow as when the vehicle is driving at a steady speed on the open road.

Therefore, two cars with the same mileage may need their transmission fluid checked sooner if the car is frequently stuck in traffic than the car that mainly drives on highways. Gartz has identified traffic congestion, high temperatures, and prolonged low-speed operation as factors that cause transmission fluid to degrade faster in Vietnamese conditions.

When should I have my oil checked earlier than scheduled?

Drivers shouldn't wait until the exact mileage mark if the car starts appearing:

Entering D or R has a delay.

Shifting gears is no longer smooth.

Slight jerking sensation when accelerating or decelerating.

Vibration when holding the throttle.

The engine revs up but the car is slow to respond.

A car operates differently when it's hot than when it's cold.

There is a burning smell or signs of oil leakage.

The gearbox is making an unusual whining sound.

These signs don't necessarily mean the gearbox is severely damaged.

However, they indicate the need to check the oil condition, pressure, and actual operational capabilities instead of continuing to wait until the scheduled date.

A perspective from Gartz

"Changing the oil regularly" should not be simply understood as:

Replace it when enough kilometers have been driven.

A proper maintenance schedule should take into account:

Number of kilometers

Usage time

Gearbox type

Operating conditions

Load

Operating temperature

The actual state of the oil

Standard of oil used

Cars that perform well on highways and cars that frequently get stuck in traffic should not be judged using the exact same formula.

The most important thing is not to change the oil as soon as possible or to try to delay it for as long as possible.

Instead, it's about checking the correct condition and using the right type of oil at the right time.

Conclude

A common misconception among customers about "regular oil changes" is that they focus solely on the number of kilometers driven.

In fact, proper maintenance must also meet the following requirements:

Under operating conditions

the right type of oil

Meets standards

Correct viscosity

Correct heat load

Accurately reflects the actual condition of the gearbox.

Even a car with low mileage can experience rapid oil degradation if it's frequently stuck in traffic, carries heavy loads, or operates in high temperatures.

Conversely, even with regular oil changes, using the wrong type of oil will not properly protect the gearbox.

Tracking mileage is essential, but understanding how the vehicle is actually used is the foundation of a proper maintenance schedule.