From March 1, 2026, the inspection of automobile emissions is officially implemented according to QCVN 85:2025/BNNMT and the roadmap in Decision 43/2025/QD-TTg of the Prime Minister.
In the early days of implementation, public opinion reflected that some car owners had to sign commitment minutes before measuring emissions, especially for diesel cars.
Mr. Nguyen To An, Deputy Director of the Vietnam Register, clarified the reasons for this regulation and specifically explained the issue of "maximum rotation".
According to Mr. Nguyen To An, the new standard divides the emission measurement results into 5 levels (from level 1 to level 5), applied according to the production year and has a separate roadmap for Hanoi and Ho Chi Minh City.
The measurement process is carried out according to national standards corresponding to each type of engine (compressed or forced combustion).
For vehicles equipped with diesel engines, emission measurement must be carried out according to the "free acceleration cycle", meaning that the registration inspector quickly pedals the accelerator table to complete the journey so that the engine achieves the largest number of revolutions according to the manufacturer's design.
This is a mandatory requirement to ensure that the measurement results are in accordance with regulations. However, in reality, many used cars are not properly maintained as recommended, even the accelerator (the part with the function of controlling the maximum rotation) is faulty or damaged.
At that time, the actual rotation of the engine may exceed the designed value, posing a risk of damage such as broken wing handles, broken cylinder caps...
The requirement to sign commitments is only a temporary solution, applied exclusively to cases where it is suspected that the actual number of turns may exceed the design limit, while the registration facility does not have enough data to compare from the manufacturer," Mr. An emphasized.
Before measuring emissions, vehicle inspectors must check technical conditions such as lubricant level, minimum oil temperature of 60 degrees C, no strange tapping sound, no congestion or uncontrolled acceleration...
If abnormalities are detected, the measurement will stop so that the vehicle owner can take the vehicle for maintenance. In case the speedometer pin touches the "red zone" - the dangerous warning zone displayed by the manufacturer on the instrument panel, it will be handled according to three situations: If it is determined that it does not exceed the maximum speed according to design, the measurement is still carried out.
If there is no basis to determine the design limit, the vehicle registration inspector must clearly explain to the vehicle owner to take the vehicle for inspection and adjust the speed control.
If the car owner still requests inspection, then they will request to sign a commitment. If there is evidence that the actual rotation exceeds the design, the registration facility will refuse to measure emissions, even if the car owner agrees to sign a commitment.
Commitments are only used for the above-mentioned cases. If any establishment requests signing outside this scope or does not clearly explain the reason, it is a violation of the Department's instructions," Mr. An affirmed.
Clarifying the concept of "maximum rotation", according to the Deputy Director of the Vietnam Register, the maximum rotation is the technical parameter specified by the manufacturer, to ensure the engine operates safely. The speed control has the task of keeping the number of rotations not exceeding this threshold.
Meanwhile, most diesel cars have a speedometer, with a "red zone" to warn the driver not to operate at a dangerous level.
However, many car owners have not paid due attention to the maintenance of the accelerator or repair at non-genuine facilities, leading to the risk of technical errors.
Currently, the database of vehicle registration centers does not have complete information about the maximum rotation according to the design of each car model.
The Vietnam Register is coordinating with manufacturers to collect and supplement this data. When completed, the requirement to sign commitments will no longer be necessary.
Mr. Nguyen To An added that the goal of the new regulation is not only to tighten emission management but also to ensure technical safety for vehicles.
According to a representative of the Vietnam Register, periodic maintenance and proper control of maximum rotation will help increase engine life, reduce emissions to the environment, limit cases of not meeting inspection and limit damage arising during use.
In the context of the new emission standards officially being applied nationwide, the management agency affirmed that it will continue to review, improve data and provide unified guidance to ensure transparent and regulated implementation, while creating maximum convenience for people.
