Bald Tires can Kill you that simple ....

 

The nail idea sounds good to me. As they say it is better to ask forgiveness than permission.

 

Who cares about the stepson, sounds like an idiot to me.... He's putting everyone else's lives in potential danger he's driving around with. Slash the idiots tires, he will understand it once he matures....Sorry I just had to say it.....

 

I agree since you offered to pay for the tire, ask to ride it and get it replaced. However Do not put yourself in jeopardy if the dealership is too far away. Ride it around the corner and trailer it and then get the tire changed. If he won't let you ride it, then pop a hole in it with a nail or screw so it looks natural.

 

STICK IT!!!! You will be doing him a Huge favor. He may get Pissed but deep down I think he will know you did it because you care about him.

 

I agree, stick it. he'll get over it.

 

If he were my son I would walk out there stick the tire and then tell him "you just got around to it" and walk away.

As someone else commented eventually he will mature and even thank you for it one day. The main thing is that you may have prevented him and/or some by-stander from getting hurt or killed.

 

My first thought but use a nail & don't tell him you did it

 

Just let the air out of it and kindly offer to help him remove the wheel. If he re-inflates it, cut it in half with a hack saw. I don't think that I'd try to hide the fact that I'm saving his life.

 

He obviously isn't a rational human, if he was you wouldn't need to tell him to change the tire. This is why I think how he will react to you cutting the tire could be an issue. I do think something needs to be done NOW!