me and my coworker put diesel in the school box truck while working a year ago. everything was cool for about a mile then the engine was like

truck slowed to a crawl and was emitting smoke, we managed to get it back to the shop but it was touch and go. amazingly the engine didn't go bad, they just had to drain it and change the filter.
we had gas fobs and lost the one to that specific truck and used another one thinking it would be fine, but the one we used was for a diesel truck and the pumps all look the same.
