Reader N.C.K said that currently, at many registration centers, during the process of checking emissions and engine performance, diesel motorbikes are often required to "press the engine" to a very high rev when the vehicle is still (unloaded). This process can be repeated many times in a short time. This potentially has a negative impact on the vehicle's engine.
Readers hope that competent authorities will seriously consider this issue and make appropriate adjustments in the coming time.
After researching, the Vietnam Register has the following opinions:
In Vietnam, emission control of road vehicles using the free acceleration method has been implemented since 1999.
Thus, the method of testing diesel engine emissions using the free acceleration cycle has been applied by Vietnam in car inspection activities for nearly 30 years.
This is the world's standard method for assessing diesel engine emissions of cars in circulation.
International Automobile Inspection Organization (CITA) as well as countries in the ASEAN and Southeast Asia regions such as Malaysia, Indonesia, and the Philippines.
This method has been internationally researched and recognized as simple, easy to implement and simulated close to the operating mode of the car in reality.
Public feedback on the risk of engine failure while measuring emissions using this method is unscientific.
Because cars before being put on the market are all researched, developed and tested by manufacturers with much harsher modes than free acceleration modes and must ensure stable running for hundreds of thousands of kilometers on the condition that they are maintained, maintained, and repaired in accordance with the manufacturer's recommendations.
Cases of damage arising when measuring emissions at registration facilities are not new after March 1, 2026, but have occurred before that, and the main reason is that the car before being put into inspection had potential problems but was not properly maintained and repaired, for example, some of the following phenomena:
Engine malfunction of engine accelerator (cannot limit engine speed or limit the maximum rotational error of the engine according to the manufacturer's design).
The car leaks lubricating oil from the engine compartment, from the turbocharger, from the cylinder leading to uncontrolled acceleration even when the user turns off the engine.
High-pressure pump error, injection needle leading to abnormal engine acceleration.
Old cu-roa wires are not replaced in the correct cycle as recommended by the manufacturer, are aging, too loose, leading to breakage during emission measurement...
These potential errors can cause vehicle damage at any time (when inspected, when used on the road...) if not detected for timely handling.
Before implementing the regulations in Decision No. 43/2025/QD-TTg, the Vietnam Register - Ministry of Construction organized training classes to guide registration facilities on implementation steps including: Carefully checking the vehicle's condition before measurement and emission, preparation steps before emission measurement, emission measurement steps... to ensure objective, transparent, fair emission measurement results and compliance with legal regulations. In addition, these measures can also detect and eliminate vehicles with potential problems and advise vehicle owners to take their vehicles to professional, reputable maintenance and repair facilities and perform maintenance and repairs in accordance with the manufacturer's recommendations before bringing vehicles to the registration facility to minimize errors arising during inspection, when driving on the road as well as to increase vehicle lifespan.
On March 24, 2026, the Vietnam Register Department organized a conference to discuss issues related to the method of measuring engine exhaust from compression by free acceleration cycle.
At this workshop, the Vietnam Register and experts discussed and clearly explained the operating mechanism of diesel engines, the basis for internationally applying the emission measurement method according to the free acceleration cycle, the correctness and suitability of this emission measurement method when applied in Vietnam, the possible causes of engine failures, measures to detect and limit engine errors and failures, and answered all questions raised by representatives of the parties.
Regarding the proposal to inspect vehicle emissions when there is load: To implement this inspection method, registration facilities must invest in appropriate inspection equipment and must have land for installation, leading to very high investment costs and it will take time to develop regulations as well as resources for registration facilities to invest in supplementation.
In the coming time, specialized agencies of the Ministry of Construction will study to be able to add some other emission measurement methods that some advanced countries in the world have just put into application such as: Measuring vehicle emissions at loaded status, checking vehicle OBD to more strictly control vehicle emissions, minimize fraud and ensure the goal of reducing pollution, protecting the environment, and protecting people's health according to the policy set out by the Party and the Government.
