Hello Nick and Scotch Lad,
115Nm is not unreasonable, and if the hand book says check to that torque then so be it.
Most torque wrenches are markes up with Imperial and meric units so it is easy to make a comparison between the two.
Dont guess the setting by hand, do it properly with a torque wrench - modern wheels and nuts can distort and become dangerous if the nuts are incorrectly tightened.