Yes, I think that would be very kind. Do it completely anonymously. Make up a simple story and help them with a new tire. That would be fabulous.
Should I help my neighbors (who I've never met) buy a new tire to replace a spare they have been driving on for 4 months? Winter snow is coming and I worry for their safety.
That would be a nice gesture, if they are willing to accept it.
Of course you should. If you have the means to do so, and they will accept your gift, then yes. If they are reluctant to accept a gift, then allow them to make small payments to you....$5-$10 dollars here and there.
If you can afford it you should. What a lovely gesture.... Make it a random act of kindness and just leave the tire on their doorstep anonymously.
( You are beautiful )
Worry not only for THEIR safety, but for anyone they share the road with .. Including your own loved ones.
Nothing wrong with helping someone in need .. It is a win win situation .. Only good can result from it.