It is understood the man regularly made fuel from used cooking oil, which he got from his local Chinese takeaway. He was using an electric drill to mix the oil with ethanol and caustic soda when a spark ignited the flames, causing an explosion. Making your own fuel is legal - the government allows people to produce 2,500 litres of biofuel a year, tax free. The AA has said more people are making their own supplies since the price of petrol and diesel began to soar at the pumps - with one estimate suggesting that 20,000 people across the UK are doing so. But the organisation said while biodiesel might work in older cars, newer engines often do not react well to home-made fuel.