I think Andy Hewitt is overstating the case in rather overly-dramatic terms of imminent car death and immense repair bills. Yes, CRD fuel pumps require full-time lubrication. Yes, they're intended to pump diesel rather than petrol. But, it is simply unrealistic and unnecessarily operatic to assert that the tiniest percentage of petrol will take out the pump, destroy the engine, necessitate complete replacement of the entire fuel system, etc.
Work through the maths: The OP has stated the vehicle had 1/4 tank of diesel when his wife drove onto the forecourt. That is probably an
*indicated* 1/4 tank, which in real volumetric terms equates to more like
1/3 tank (accounting for the reserve quantity of fuel in the tank when the gauge indicates Empty). He further states his wife put in 11 litres of petrol followed by 40 litres of diesel.
Working from the 1/4-tank start (worst case), that means 40 litres diesel plus 11 litres petrol = 51 litres = 0.75 tank volume. Therefore, 11 out of
68 litres are petrol, and 57 out of 68 litres are diesel. Therefore, the tank contains -- worst case -- 16% petrol.
Working from the 1/3-tank start (best case), that means 40 litres diesel plus 11 litres petrol = 51 litres = 0.67 tank volume. Therefore, 11 out of
76.5 litres are petrol, and 65.5 out of 76.5 litres are diesel. Therefore, the tank contains -- best case -- 14% petrol.
Diesel fuel is sold all over the world. With the exception of North America, so is the CRD PT Cruiser. The diesel fuel sold all over the world is not the same. Its formula is varied to account for local climatic conditions. It is thinned considerably for cold regions, otherwise it would be unusable.
In real terms, therefore, the effect is as if the OP had bought a tankful of diesel in winter in Norway or Sweden.
Mr. Hewitt, you are making a much bigger, scarier deal out of this than it almost certainly really is.