These bio-oil should be used in car engines ideally. I understand that heat content is an important parameter, along with smell, viscosity, knocking etc.
HHV, LHV, water content, mechanical particles( charcoal, sand etc.), ability to mix with fossil fuel and engine oil, temperature stability, freeze point.
It is important to check cloud point, pour point, flash point, acid value, iodine value, saponification value, rancidity, density, viscosity, water contnet, ash content etc.