However, E10 may result in slightly weaker engine performance compared to E5.

The Ministry of Industry and Trade (MOIT) has proposed that from January 1, 2026, all vehicles and motorcycles in Vietnam will have to use E10 gasoline (blended with 9-10 percent ethanol) as it is the only type of gasoline available on the market.

This information has drawn attention fro, the public , particularly drivers, car manufacturers, and technical experts. Many are concerned that E10 could affect vehicle performance and engine longevity, especially for older vehicles.

Biofuel gasoline 

In an interview with VietNamNet, Dam Hoang Phuc, Director of the Automotive Engineering Training Program at Hanoi University of Science and Technology, said that E10 is a practical and feasible solution to reduce emissions, aligning with Vietnam’s COP26 commitment to achieve “net zero” by 2050.

Recently, a research team led by Phuc conducted tests to evaluate vehicle performance using different fuels, including RON 95-V, E5 RON 95-V (E5), and E10 RON 95-V (E10).

The study was conducted on the latest Toyota Corolla Cross models (2023), including both pure gasoline (V) and hybrid (HEV) versions, which ran on various roads such as urban roads, highways, and expressways during peak and off-peak hours.

The team measured two harmful gases affecting humans and the environment: hydrocarbons (HC) and carbon monoxide (CO). The results showed that E5 and E10 produced 7-16 percent less HC and 9-15 percent less CO compared to A95 gasoline.

Comparing the two biofuels, E5 and E10, the study on Toyota Corolla Cross V (pure gasoline) found that E10 reduced HC emissions by 9 percent and CO emissions by 5.5 percent compared to E5.

However, for the hybrid (HEV) version, E10 emitted 11.5 percent more HC but still reduced CO emissions by 4.5 percent compared to E5.

E10 effect on engine performance

The use of biofuels to reduce harmful emissions has been studied in many countries worldwide. It is a cleaner, more environmentally friendly fuel option that benefits public health and helps mitigate the greenhouse effect.

However, many people remain concerned about whether biofuels affect engine performance or lead to higher fuel consumption compared to traditional gasoline.

HUST’s study on Toyota Corolla Cross showed that E5 provided the highest power output across all speed ranges (60-120 km/h) for both pure gasoline and hybrid versions. In contrast, E10 delivered the lowest power output in most speed ranges, with a difference of about 1-5 percent compared to A95.

Vehicles using E10 feel slightly less responsive than those using other fuels. Specifically, the acceleration time from 10-100 km/h for E10 was 10.49 seconds for the pure gasoline version and 9.19 seconds for the hybrid, compared to 9.62-9.21 seconds for A95 and 8.56-8.13 seconds for E5.

Thus, E5 was the most optimal fuel for engine power. E10 is environmentally friendly, but its performance is not as high as E5 or regular A95. In return, E10 is more fuel economical than A95 at high speeds (above 80 km/h).

Phuc noted that the study was conducted on a single vehicle model but still highlights the advantages and drawbacks of biofuels, particularly E10.

Whether E10 is suitable for a specific vehicle depends on various factors, and users should carefully review their vehicle’s manual to ensure they select the most appropriate fuel.

“Most vehicles manufactured in the last 10-15 years are designed to use E10 without significantly affecting performance or engine durability. However, each manufacturer may provide specific technical recommendations for their models, so users should review the manual or consult with the manufacturer’s experts,” Phuc said.

In an earlier interview with VietNamNet, Bui Ngoc Bao, Chair of the Vietnam Petroleum Association, noted that from 2026, the market will phase out traditional mineral gasoline and E5, leaving only E10. 

This is considered a decisive step after multiple delays in the biofuel roadmap under the Prime Minister’s Decision 53.

Bao affirmed that E10 is an environmentally friendly fuel widely used in the US and EU and is compatible with most modern vehicles, including those meeting Euro 3-4 standards. 

However, E10 has high moisture absorption, which can lead to water separation if stored for long periods, potentially causing sediment buildup or corrosion of rubber gaskets in older vehicles.

Hoang Hiep