Bandung. Indonesia has begun large-scale trials of a 50% biodiesel fuel blend for vehicles under its planned B50 program, which authorities aim to make mandatory in June.

The Energy and Mineral Resources Ministry said intensive testing began on Dec. 9, 2025, involving several vehicle models widely used in Indonesia, particularly sport utility vehicles such as the Toyota Fortuner, Mitsubishi Pajero, and Nissan Terra.

Director General of Renewable Energy Eniya Listiani Dewi said the B50 trial also covers the mining sector, agricultural machinery, marine transport, power generation, and railways.

B50 is a fuel blend consisting of 50% fossil diesel and 50% Fatty Acid Methyl Ester (FAME), a biofuel produced from vegetable oils, particularly palm oil.

“By May, all automotive trials for vehicles weighing under 3.5 tons are targeted to reach 50,000 kilometers. After that, all engines will be inspected,” Eniya said. “Trials for vehicles above 3.5 tons have already completed the target distance of 40,000 kilometers.”

So far, engine conditions and fuel filters remain in good condition and within standards recommended by manufacturers after using B50, she added.

B50 testing team head Cahyo Setyo Wibowo said preliminary results showed no significant impact on fuel consumption.

“The efficiency remains within the range claimed by each manufacturer,” Cahyo said. “This testing is being conducted together with engineers and technicians from the manufacturers. Most importantly, fuel consumption remains within their specified limits.”

He added that no engine adjustments or modifications were made during the trials, with all vehicles tested in standard factory condition.

Once the target mileage is completed, the test vehicles will undergo overhauls to assess internal component conditions in detail.

“We will inspect deposits, filter conditions, and injectors. Everything is being done jointly with the manufacturers because they understand the technical standards,” Cahyo said.

Authorities said B50 production is being closely supervised and must meet national quality standards to minimize issues such as deposit formation, a common concern with biodiesel use.

However, Cahyo said deposits are influenced not only by fuel quality but also by environmental factors.

“We are a tropical country with varying humidity levels. That has a major impact. That is why testing is also being conducted under different conditions, including cooler areas such as Lembang,” he said.

Toyota Astra Motor Marketing Director Ernando Demily said B50 testing on the Toyota Fortuner had so far shown no fuel-system related problems.

Despite encouraging early results, he urged motorists to continue following manufacturer recommendations.

“We always advise users to use fuel that meets the specifications stated in the owner’s manual and to carry out regular maintenance to keep the vehicle in prime condition,” Ernando said.

Toyota recommends diesel fuel with sulfur content of no more than 50 parts per million and a cetane number of 48 or higher, specifications typically found in premium diesel products.

The B50 trials also involve a Mercedes-Benz bus and four truck models: Hino truck, Mitsubishi Canter, UD Truck Quester, and Mercedes-Benz Axor.