I have always wondered why there is no drop-in biogasoline like there is drop-in biodiesel. For example, NEXBTL by Neste can be run at 100% mixture in conventional diesel engines. It is different from conventional fatty acid methyl ester type of biodiesel that may require engine modifications. Because NEXBTL is chemically similar to conventional petrodiesel, no modifications are needed.
In contrast to this, the bio-equivalent of gasoline is generally ethanol. Ethanol fuel has poor cold start properties and may require engine component replacements. For example, ethanol may damage fuel lines and seals.
It seems strange to me that if drop-in biodiesel has been produced, why drop-in biogasoline has not been produced. Instead, they produce ethanol the use of which at high concentrations requires vehicle modifications. It feels especially strange to me that the R&D effort was spent in developing drop-in biodiesel, because diesel engines have higher NOx pollution and particulate matter pollution than gasoline engines.
Is there a reason that makes producing drop-in biogasoline much harder than drop-in biodiesel?
I'm especially worried about the situation, because I have a gasoline car that allows running only 10% ethanol and they are already selling 10% ethanol in gasoline here. The future targets have a much larger bio-component in transportation fuels. I'm not sure if it makes sense to buy a more environmentally friendly car at great cost either, because e.g. the Prius also allows only 10% ethanol, meaning the newly purchased car could become obsolete very soon.