I can attest to that , I got to see the dye put in , I worked on the machine at a loading dock for tankers and seen the dye being dumped , a gallon into a 5000gallon tanker , and talked with the guy , he showed me all the different colored dye they use and how it all worked , red for highway , and I think it went purple for marine , etc , etc , they had quite a few different colors in the locker , he said that all the fuel nowdays is low sulphurThere is no differnce. Off road has red dye in because in is not subject to road tax. Get caught with off road in your pick up, huge fine. Red dye is solely to mark it. If off road is easy for you to source, then it is a no brainer to run it. Why pay road tax to run something that is not on the road.