In ye olden days a bunch of us would help out a mates sister who worked for a charity that provided care to families of kids with special needs. We'd give her a hand on the respite camps she ran: basically it was a bunch of blokes in their early 20s filling a minibus with kids, taking them to the beach for the day, then heading to the pub to get pissed sans kids.
My mate Rob whose sister worked for the charity had a heavy vehicle license, so he drove the mini-bus while the hyperactive rioting went on in the back. Returning the kids after the day at the beach, his sister gave him a fuel card and told him in front of everyone to refuel "WITH DIESEL ONLY".
Closer to home we pulled in to re-fuel the bus and one of the kids with ADHD and tourettes starts yelling at Rob "Diesel only, do what your sister tells you to do". Rob is cranky at the best of times, so he started back at this kid to sit down and mind his own business. Rob rocks up to the bowser and this kid is now hanging out the window "Rob you dickhead, Diesel only!" With the fuel still pumping Rob is yelling back at this kid to sit down and shut up until one of the lads looked out and told Rob "Mate, that's unleaded". This kid was giving it to Rob so much I thought he was going to cry, but it was only an entree to the grief he copped at the pub and the decades after.
We ended up having to unload the kids for a game of frisbee along the Western Port Highway while the bus got pushed onto some vacant land near the servo and a mechanic who happened to be refueling at the same time took charge and emptied the fuel tank on to the ground.
Close to 20 years later whenever anyone sees Rob get in or out of a car, it's become customary to ask him if it's a diesel or petrol engine to get the guaranteed grumpiness out of him. Rob being Rob, I think the part that irritates him the most is that his sister pulls out the I Told You So's and he's got nothing. Good times.
Here's hoping your car issues are solved as painlessly as possible.