If you observe closely on your chain, you can see that it is composed of O rings and X rings. By lubrication we are supposed to insert the fluid between the ring metal to reduce the friction and make the movement easier. read more
Engine oil costs more than the chain lube. It is not economical to be using engine oil. In the short run, using engine oil as chain lube might work but in the long run, this would seriously damage the chain. read more