Originally Posted by 3i Jim

I forgot to mention my mondeo will spin the wheels in 3rd on damp greasy roads in the winter. However it wouldn't spin up in 3rd with supermarket fuel. I know it's very unscientific but I feel there's a connection in performance between supermarket and branded fuel. I've heard diesel has to have a minimum of 10% biofuel mixed in for it to comply with eu legislation and that branded fuel only put the minimum required. However supermarkets like to add around 15% biofuel (watering it down) Biofuel fuel is a living substance that can form a fungus/sludge in the fuel tank. I could be wrong though. Why is it you only hear of bad batch fuel at supermarkets and not at the branded petrol stations?