Overtorqueing can have bad results. On alloy wheels it can crack the rims. You can distort the rotors. You can fatigue the studs and lugnuts. On the shell type lugnuts you will spin the covers, especially when you try to remove them. Do yourself and your car a favor and get a torque wrench. They aren't expensive and it makes you more professional. 60 is NOT "great" for most cars. Always look up the manufacturer's recommended torque and use it. It is usually listed with tire pressures in the owner's manual. The ONLY time you tighten lugnuts by feel is if you have to change a tire on the side of the road.