Top 5 common misconceptions customers have about automotive transmission fluid.

Are all transmission fluids the same? Is thicker fluid better? Or is it unnecessary to check if your car isn't showing any error codes? Let Gartz clarify 5 common misconceptions about ATF fluid and how to choose the right fluid for modern transmissions.

Gear oil is not just for lubrication.

Many car owners pay close attention to engine oil but overlook transmission fluid. When advised on maintenance, many still believe that transmission fluid only needs to be in the correct quantity, the right color, and changed according to mileage.

In fact, transmission fluid performs many other important functions:

- Hydraulic pressure transmission

-Lubricate the parts.

-Friction control

-Assists with the gear shifting process.

-Cooling the gearbox.

Especially with modern transmissions, even a slight mismatch in viscosity or friction properties of the oil can alter driving performance, even if the vehicle doesn't show any obvious faults.

1. All transmission fluids are the same.

This is the most common misconception.

Outwardly, many types of transmission fluid look quite similar in color and consistency. However, each product may differ in the following ways:

-Viscosity

-Friction properties

-Heat resistance

-Additive system

-Technical standards

-Compatible gearbox type

Traditional automatic transmissions, CVT transmissions, and dual-clutch transmissions operate on different principles. Therefore, they cannot be used interchangeably with the same type of oil.

CVT fluid needs to control friction between the steel belt and pulley. Meanwhile, fluid for multi-speed automatic transmissions must support a fast and precise hydraulic response system.

The correct question is not:

-"Is this oil any good?"

It should be:

-"Does this oil meet the specifications for the car's transmission?"

See also:Gartz Gear Oil CatalogGartz's product catalog currently categorizes products by transmission type, such as 9G-HP, G6, 6HP, ATF G4, CVT RED, DCTF, and CVT GOLD.

2. The thicker the oil, the better the protection.

Many car owners believe that thicker oil creates a thicker protective layer and helps the transmission last longer.

This is not true for modern automatic transmissions.

If the oil is too thick compared to the design specifications:

-Oil circulation is slow.

-Slow-response hydraulic system

-The solenoid valve is operating at the wrong time.

-A delay may occur when entering D or R.

-The gear shifting process is not smooth.

Conversely, oil that is too thin can lead to unstable oil pressure, a thinner protective oil film, and reduced friction control.

Therefore, the appropriate oil is not the thickest oil, but rather the oil with the correct viscosity required by the gearbox.

Gartz 9G-HP is developed for 8–9 speed automatic transmissions where viscosity, oil pressure, and friction characteristics need to be precisely controlled.

3. Oils of the same color can be used interchangeably.

Color is not a technical criterion for determining whether an oil is suitable or not.

Two oils of the same color can still be completely different in:

-Viscosity

-Friction properties

-Manufacturer's standards

-Heat resistance

-Compatible gearbox design

For example, the fluid for a 4-speed automatic transmission and the fluid for a CVT transmission may both be red, but they are not interchangeable.

Gartz ATF G4 is designed for 4-speed automatic transmissions and some older transmissions. Meanwhile, Gartz CVT RED is for continuously variable transmissions (CVTs) that use metal pulleys and belts.

Therefore, you shouldn't choose oil based on color, packaging, or external appearance.

4. If the car hasn't displayed any error codes, it means the transmission fluid is still good.

The transmission doesn't necessarily need to display an error code immediately when the oil starts to degrade.

In many cases, the oil has degraded in viscosity, pressure transmission capacity, or friction characteristics, but the system has not yet detected a fault significant enough to trigger an alert.

The car may start showing small changes such as:

-Shift to D or R at a slower speed.

-Shifting gears is no longer smooth.

-The slight vibrations only appear when the car heats up.

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

-The gearbox feels sluggish compared to before.

These symptoms don't necessarily mean the transmission is severely damaged. However, this is a good time to have it checked instead of continuing to use it until the warning light comes on.

5. The more expensive the oil, the more suitable it is for the car.

A high price does not necessarily mean compatibility.

Even a high-quality oil with the wrong viscosity or that doesn't meet the correct standards can still cause the transmission to operate erratically.

The order of priority when choosing transmission fluid should be:

-The right type of gearbox

-Meets technical standards

-Correct viscosity

-Correct friction characteristics

-Clear origin

-Proper oil change procedure

After meeting the above conditions, brand and price are the next factors to consider.

-The best oil isn't necessarily the most expensive.

-The best oil is the oil that is most suitable for the vehicle's transmission.

A perspective from Gartz

Not all transmission fluids are created equal.

A suitable product needs to meet the following requirements simultaneously:

-Gearbox design

-Manufacturer's standards

-Required viscosity

-Friction properties

-Actual operating conditions

Using the right oil from the start is often much simpler and more economical than dealing with the lag, vibration, or wear that develops after using the wrong oil for an extended period.

Conclude

The five most common misconceptions about automotive transmission fluid include:

-All transmission fluids are the same.

-The thicker the oil, the better the protection.

-Oils of the same color can be used as a substitute.

-The fact that the car hasn't shown any error codes means the oil is still good.

-The more expensive the oil, the more suitable it is.

In modern gearboxes, oil is used not only for lubrication but also directly participates in pressure transmission, friction control, heat dissipation, and gear shifting.

Therefore, the most important principle is not to choose the most popular, thickest, or most expensive oil, but to choose the right oil according to the specifications of the vehicle's transmission.