Honda bikes(95-110lbs oil pressure)had similar issues and it wasn't until i bought the factory manual that i found the cure,they recommend 10nm on a cap wrench.sure enough the leaks stopped on the bikes that had chronic weeping at the filter.As this was a regular spin on filter i think the figure is relevant to automotive type filters,at this torque there is no problem removing the filter,i use a 3/8 drive torque wrench and cap wrench on all filters at 10nm and have no problems.To me it just makes sense to use an accurate(when space permits) figure rather than hand tight.
