This is adorable, OP. You're a saint. Try teaching her right from wrong and how to distinguish the petrol properly. kudos for your patience and generosity.

While technically putting in the wrong fuel is a relatively easy mistake to make - At least in the USA the car manufacturers and the gas stations are pretty clearly labeled diesel vs gasoline. Either wife was irresponsibly careless or stupid in thinking she could save money by buying gasoline in place of diesel… If your wife is like mine, she might sometimes think that defending your part of the discussion is unfair and she’s the only one who gets to defend their part of an argument - Especially when the facts are clear that she made a mistake… If wife has a job, let her pay for the repairs. If not then you’re paying anyway… After my wife had ruined multiple loads of laundry (bleeding colors) by overstuffing the washer, I accepted that my share of the chores was doing the laundry. I suggest avoiding having wife fueling the car if possible. At the very least, make sure the fuel port is clearly marked “diesel only”… By the way, I would never, ever buy a diesel automobile. It turns out the “clean and efficient diesel” was all a lie and a scam by car manufacturers to get around government requirements. Google “dieselgate”. It makes sense for very large vehicles like trucks but not generally for ordinary autos. But then we are dealing with what is and not what you wish it were.

You did get the weird car. Is she wrong?

Why don’t we chug on over to mamby-pamby land and get you some self-confidence, ya jackwagon?

My husband put the wrong fuel in my car 3 times within 2 months, our car dealership said it’s very common