A colleague put 20 liters of Plant (red) diesel in my 18 plate Insignia 1.6 'whisper' diesel auto. The fuel was waiting fir disposal.  There was about 20 liters of normal diesel in already so it us about 50/50.  I have not started the engine as yet.  Will it be ok to use or will it not run? Any silly sensors?

Hi John, red diesel shouldn't cause any running problems, as it is only a dye to distinguish it from road fuel, as it stands being a 50/50 mix, you should be fine. The only problem you might have, is if VOSA or HMRC do a random check, and see you've had red in the tank. Using red diesel in road vehicles is unfortunately illegal, and your vehicle could be seized until you pay the duty that would be owed on the difference between road and plant fuel. And they can also get you to pay to have your fuel system cleaned to remove the red dye that is left behind.