I put 25 litres of petrol on top of two gallons of diesel in my wife's diesel engined car, then drove five miles before the engine juddered and I realised my mistake.

Pulled up immediately and called out a firm called Fuel-Fix. They pumped out the tank, flushed the engine and gave us a small amount of diesel, laced with some sort of lubricating additive, then sent us on our way.

I'm worried about the long term consequences. The internet offers no reassurance and I've read that damage to the fuel pump and injectors, etc, could cause catastrophic engine failure later on.

Is there anything that could help recondition the engine internals? What tell-tale problem signs should I look out for?