Hey Oilburners, I thought you might find this interesting, regarding red dye diesel. Use this info at your own peril, however, if caught using it, you may have a leg to stand on if you decide to fight the fines.... no guarantees implied, represented nor promised by yours truly: The EPA Requirements U.S. EPA regulations require “visible evidence of the presence of red dye” to identify high sulfur fuels when they leave the refinery. In practice, this requires refiners to add a level of red dye that is equivalent to no more than 0.75 pounds/1,000 bbl (ptb) (2.14 mg/L) of a solid Solvent Red 26 dye standard. Solvent Red 26 was chosen as the standard because it is a unique chemical available in pure form. Diesel fuels are actually dyed with liquid concentrates of Solvent Red 164 because this dye is more fuel soluble and less costly than the standard. Solvent Red 164 is a mixture of isomers that are very similar to Solvent Red 26, except the former incorporates hydrocarbon (alkyl) chains to increase its solubility in petroleum products. Any red dye observed in the fuel of a vehicle in on-road use triggers a measurement of the fuel’s sulfur content. Penalties are assessed based on the actual sulfur content of the fuel, rather than simply on the presence of dye. As of June 2012, only heating oil will require red dye for EPA purposes. By then, on-road, non-road, locomotive, and marine diesels will all be ULSD. We do not typically use heating oils in SoCal, so red dye's at the pump are for "off-road/commercial" use. Going through all the trouble with an inspector, who really knows nothing more than:"Write a ticket! Write a ticket! Write a ticket!" may be a PITA, then going to court to present the facts, potentially getting a fine anyway (We all know the courts have ceded to the government all of our rights, so expect no sympathies from a judge. They too are in the business of collecting fines from "The People"),but in case you end up in the situation, at least here is a summary of the goings on of Red Dye diesel. For those of you who like reading technical documentation, I'm sick and do so, here is a link from Chevron where the quote came from: http://www.chevronwithtechron.com/products/documents/Diesel_Fuel_Tech_Review.pdf Now, that said in relation to Red Dye and on/off road differences by the EPA, the IRS is not so hip to the trip if you're not paying the on-road taxes. Here is how the IRS may see it: The Internal Revenue Service (IRS) Requirements U.S. IRS regulations require that tax-exempt diesel fuels, both high-sulfur and low-sulfur, have a minimum level of a Solvent Red 164 dye that is spectrally equivalent to 3.9 ptb of the Solvent Red 26 dye standard. This level of dye is more than five times the amount required by the EPA regulations. The IRS contends that the high dye level is necessary to allow detection of tax evasion even after five-fold dilution of dyed fuel with undyed fuel. The IRS want 5 times the amount of dye required to color fuel, just so they can bust your fanny 5 tanks full later of non-red dye fuel!! Boy! Talk about deep convictions! So there you have Chevrons version of the rules. Do as you find fit, and at your own risk, but I thought it might be interesting for the non-traditional burners to get a better grasp on the goings on with red dye. I hope this is useful.