I am looking at buying an impact wrench to save time when removing my wheels? I tried a 14.4v gun today but it would not even look at them. I have my wheel nuts tightened to 120nm, will a 18v gun rated at 195nm remove them no problem? If you have any suggestions or if you use one on a regular basis what is the minimum amount of torque needed to slacken the nuts? Thanks, Stevie.