I stupidly put petrol in my almost empty diesel car - about £3.50 worth before I realised. The 70 litre tank was almost empty. I didn't switch on the engine - some muscly men helped me move it out of the way. I rang 'Fuel Doctor' 0845 4590 000 (cheaper than the RAC), he took my details and I was about to pay him but when I told him the amounts involved he immediately said it would be fine to fill up as it will then be so dilute. Is this fantastic honest service, or is he wrong?