Biological E5 ethanol, produced by Vietnam National Oil and Gas Group, officially went on sale on August 1, but the environmentally friendly fuel has yet to be embraced by motorists.

The fuel, a mixture of 95 percent A92 petrol and 5 percent bio-ethanol produced from cassava, tobacco and sugar cane, is now available at 20 filling stations in Hanoi , HCM City , southern Ba Ria-Vung Tau province and northern Hai Phong and Hai Duong provinces.

However, demand is limited.

At Hanoi-based Thai Thinh filling station, there were typically long queues of drivers waiting for A92 petrol on August 2, but few callers for E5.

Nguyen Van Duc, a petrol pump attendant, said few motorist wanted E5 petrol, even though it was cheaper than other kinds of fuel.

E5 costs 15,500 VND (0.8 USD) per litre, while regular A92 costs about 16,000 VND (8.4 USD) per litre.

"Many people do not know about this kind of petrol, while those that are familiar with it are hesitant to change their behaviour and are not sure about quality," Duc said.

However, he said the number of motorists using E5 had gradually increased partly because it was cheaper but also because it was "cleaner and safer."

He said motorists should be made fully aware of E5's benefits.

"I didn't know that E5 was already on sale," Tran Hoang Nam , a motorist from Hai Ba Trung district, said.

"I have no idea if the fuel is as good as regular petrol, so I will wait until it becomes more popular," he said.

Nguyen Xuan Son, director general of Viet Nam Petrol Oil Corporation, said E5 had been thoroughly tested to ensure it was suitable for all vehicles.

E5 petrol was launched as part of the Government's biofuel development master plan (up to 2015).

E5 petrol will next go on sale at three stations in central Da Nang city, three in central Thua Thien-Hue province and five in the Mekong Delta's Can Tho city.

It will be sold at more than 4,000 stations by the end of 2012./.