Can you run fuel oil in a diesel motor?

Running fuel oil in a diesel motor is generally not recommended, as fuel oil typically has a higher viscosity and different combustion properties compared to diesel fuel. While some diesel engines may be able to handle a small proportion of fuel oil, doing so can lead to issues like poor combustion, increased emissions, and potential damage to the engine. It's important to consult the manufacturer's guidelines and use fuels specifically designed for diesel engines.