I recently read Andy Weir's Project Hail Mary and was taken aback by his use of the word "tyre" considering both he and the publisher are American. It was also

I recently read Andy Weir's Project Hail Mary and was taken aback by his use of the word "tyre" considering both he and the publisher are American. It was also the only word I noticed with distinctive British spelling -- for example, "color" was left without the "u"