Discussion on question by xdtTransform: How to tell a colleague that I want to stop sharing the ride?

You mistake is knowing Joe's salary and comparing it to yours. It seems silly to change your mind about sharing a ride just because he was making 28% more than you and is now making 39% more. Sorry, you are acting in a very immature manner. Maybe you could just tell him you don't want to ride with him any more because he got a raise. While immature, at least it would be honest.

What ever you decide to do, don't make it about the salary. All that will do is make an awkward situation worse.

@xdtTransform So Joe offered to pay a correct amount, you insisted on a way lower compensation "because he's a nice guy" and now want to take away a reasonable means of transportation for Joe because you define interpersonal hierarchies based on salaries? Are any of the car trips done purely for Joe or are all destinations shared between the two of you?