THESE past three years Tatang Hernas Soerawidjaja no longer carries around jerry cans on the back of his car. Since Pertamina started selling biodiesel with the trade name bio-solar (B5) at several gas stations, he stopped mixing diesel with biodiesel liquids. Neither does he need to give on-the-spot “lectures” to anyone who needs to know how to mix biodiesel liquids.

In the past, said Tatang, gas station employees always asked him what liq