Q: Tire lug nuts are extremely hot after driving. Is this normal?

If the brakes have been applied, heat will be conducted from the rotor to the wheel and thence to the lug nuts. However, the braking has to be fairly significant and continuous, such as in stop and go driving, for the wheel itself and the lug nuts to get hot. If you are driving on the highway, with your foot off the brake pedal, and pull off into a rest area, the lug nuts and wheel should be cool to the touch. Indeed, if you stopped gently enough (i.e., mostly coasting), you can sometimes touch the rotor itself. The bottom line is, if the wheel hub area, including the lug nuts is hot to the touch, in the absence of much braking, there is possibly an issue with the wheel bearings or the brake caliper. A failing wheel bearing will generate friction but if your wheel bearings are failing you will always hear a fair amount of noise from the affected wheel(s). An additional possibility is the brake caliper is sticking and you should suspect that possibility if the brake rotor is very hot, yet you have not applied the brakes much in the period prior to checking the rotor (or rotor temperature varies significantly from one side of the car to another). To resolve this, you can request a wheel hub diagnostic and the responding certified mechanic will check to see if there is a stuck caliper (or comparable in effect brake system defect) and/or a defective wheel bearing. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.