Does that suggest you could win a fuel tax case, if you have journaled every fill, dealer & location? Maybe be helpful.Just checked one of my card lock bills and the difference is 11.5C per liter. The road tax on clear is 14.3 C, but the base on dyed is a bit higher.
I have found it not worth the risk, have been dipped once with no problem. A friend was dipped up north and the sample was send for lab check, it came back with trace amounts of the dye tracer. He was fined and checked with his supplier. ( truck was never filled with dyed diesel!?) They filled his dyed tank was first and the clear next without cleaning the fill hose on the truck. That was enough to fail the test. His supplier paid the fine and explained the issue to the enforcement branch. He avoided a full audit (can go back 7 years as by tax law). This is why I only use card lock as it provides for easy and reliable records incase one does get an audit.