Optimal tips for car owners using E10 gasoline.

Experts assert that most vehicles can use E10 if properly maintained, while authorities are committed to closely monitoring quality across the entire system.

As one of the first people to use E10 gasoline after it was widely adopted, Ms. Thy (residing in Trung My Tay ward, Ho Chi Minh City) said that before refueling, she was advised by gas station staff not to let the fuel tank get too empty and to avoid getting water into the tank.

Proactive vehicle maintenance

The motorbike that Ms. Thy is using was purchased in 2004, and for many years it has only undergone minimal maintenance, mainly regular oil changes and repairs when problems arise. Therefore, she couldn't help but feel worried when switching to E10 gasoline.

People in Ho Chi Minh City are filling up with E10 gasoline.

"After a day of using E10 gasoline, the car is still working normally, with no unusual signs yet. However, I am still continuing to monitor it," Ms. Thy shared.

For Mr. Duc (residing in An Lac ward), the use of E10 gasoline hasn't started yet because his car still has some mineral gasoline in the tank. However, to prepare for the switch, he has proactively maintained his car more thoroughly, replacing spark plugs, checking gaskets, fuel lines, and some rubber parts that are at risk of deterioration.

People should inspect and maintain their motorbikes before using E10 gasoline.

According to Associate Professor, Dr. Do Van Dung - Chairman of the Ho Chi Minh City Automobile and Power Equipment Association, former Rector of Ho Chi Minh City University of Technology and Education, since E10 gasoline was piloted and then widely implemented in Vietnam, the reactions of users have always been quite diverse.

Some users reported smooth vehicle operation and only a slight increase in fuel consumption. However, many others experienced issues such as difficulty starting, loss of power, sudden engine stalling, weak engine performance, illuminated fault lights, or excessive fuel consumption.

Is it simply a matter of "luck or chance"?

According to Associate Professor Dr. Do Van Dung, these differences do not stem from luck or subjective perception, but rather from fairly clear technical causes.

The first cause lies in the fuel storage system at gas stations. Ethanol in E10 gasoline has strong hygroscopic properties, easily absorbing moisture from the environment through gaps and the ventilation system of the storage tanks. When the amount of accumulated water exceeds the permissible limit, ethanol and water will separate into a distinct layer and settle at the bottom of the tank, while the lighter gasoline floats to the top.

In fact, many fuel storage tanks in Vietnam were previously designed for traditional E0 gasoline and have not been upgraded to be compatible with E10 bioethanol. This increases the risk of water separation.

For older vehicles, owners should check and clean the fuel tank, replace the fuel filter, and inspect the fuel lines and rubber seals before regularly using E10.

If people refuel when the tank is just full or when there is a high consumption rate, the fuel is usually consistent and less likely to cause problems. Conversely, with tanks that have been sitting for a long time, the pump nozzle may draw in water and ethanol sediment at the bottom. When this mixture enters the engine, the vehicle is prone to problems such as difficulty starting, loss of power, stalling in the middle of the road, or weak performance.

The hot and humid climate in Vietnam further complicates the issue, as the high humidity causes the tanks to absorb water more quickly.

In addition, ethanol has strong cleaning properties. When introduced into older vehicles that haven't been thoroughly cleaned, ethanol can dissolve the dirt and rust that have accumulated over the years in the fuel tank. These impurities then travel with the fuel into the system, clogging fuel filters, injectors, or carburetors, causing the vehicle to lose power, reduce performance, and consume more fuel.

Furthermore, ethanol also affects rubber and metal components. In older vehicles, rubber gaskets, seals, or fuel lines can swell, become brittle, or degrade more quickly. When combined with water, ethanol also accelerates corrosion and rusting of metal parts in the fuel system.

According to this expert, newer car models are usually designed by the manufacturer to be compatible with ethanol, so they experience fewer problems. Meanwhile, older vehicles that have not been inspected or had their fuel systems cleaned before switching to E10 are the most prone to malfunctions.

E10 bioethanol fuel is sold at all gas stations in Ho Chi Minh City.

To minimize risks, users should prioritize refueling at busy stations to reduce the time fuel sits in the tank; and avoid leaving the vehicle idle for too long when the tank is full of E10 gasoline. For older vehicles, owners should check and clean the fuel tank, replace the fuel filter, and inspect the fuel lines and rubber seals before regularly using E10 gasoline.

Closely monitor gasoline quality.

Regarding the public's concerns, Mr. Nguyen Khac Hieu, Deputy Head of the Energy Management Department of the Ho Chi Minh City Department of Industry and Trade, said that the transition to a new type of fuel is understandable and that the authorities have proactively prepared for it from an early stage.

According to Mr. Hieu, currently, the number of businesses licensed to blend E10 gasoline nationwide is less than 10. These are all large-scale businesses in the petroleum industry, with strict management processes and extensive experience in fuel blending. Thanks to this, regulatory agencies can easily trace the origin and determine responsibility if any quality issues arise.

The Ho Chi Minh City Department of Industry and Trade is working closely with the Department of Science and Technology to monitor the quality of E10 gasoline on the market. When any irregularities appear, the relevant authorities will conduct inspections and take immediate action against the involved parties.

Notably, the Ho Chi Minh City Market Management Force maintains a 24/7 duty roster to monitor gasoline and oil business activities throughout the city. Citizens who detect signs of violations can report them directly through the hotline of the Department of Industry and Trade or the Market Management Sub-department for timely reception and handling.

Mr. Hieu added that since the Ministry of Industry and Trade issued Circular No. 50/2025, Ho Chi Minh City has proactively worked with key traders and distributors to review the entire infrastructure system serving the E10 gasoline business.

Currently, the city has two petroleum production enterprises, 12 wholesale traders, 65 distributors, 425 agents, and 1,176 retail outlets serving over 14 million people. Essentially, the traders have the necessary infrastructure ready to launch the E10 gasoline business.

Source: https://znews.vn/mach-nuoc-toi-uu-cho-chu-xe-dung-xang-e10-post1656276.html