I believe they use more than just dye, I have heard (tho of course it could be ■■■) that VOSA can test the exhaust fumes for rebated fuel.
Harry Monk:
I believe they use more than just dye, I have heard (tho of course it could be ■■■) that VOSA can test the exhaust fumes for rebated fuel.
this is true, but further checks are only carried out if the diesel looks a bit red, or green.
and i’ve only been checked by HMRC for dodgy diesel, not by VOSA.
H.M. Customs and Excise can tell if there has been red diesel in the tanks its like tomato stains on your kids clothes try as you might they wont 100% go.Dont use the stuff if you are not entitled to use it.
There is no difference between red and white, (pre biofuel), it doesnt knacker engines, easy start knackers engines, the astra simply wanted new heater plugs and would have packed up anyway.
I have delivered red hmce approved marker dye to the oil refineries in a past life, and when I owned a bellytank hmce told me as long as I kept it under 3% red mix, they were happy.
About £0.50ppl is the difference, the red has been catching up fast 
, used to buy it at £0.04ppl