Apart from farming, the primary use for red dyed diesel fuel is in home heating oil.
Essentially, there’s little substantive difference between the heating oil you get and the on-road diesel you buy for your truck at the gas station. They’re both #2 diesel. And now they’re both going to be ultra-low sulfur diesel fuel (ULSD). That wasn’t true a couple years ago when the EPA still allowed “off-road” diesel to retain a higher sulfur content than on-road diesel. But that dispensation ended in 2014. So it’s most likely that the red home heating oil you buy for your heating system is going to be ULSD.
The switch to red ULSD makes your heating oil more prone to microbes and sludge than in years past. Most people don’t exactly check their fuel oil tanks, which makes the situation a recipe for problems. Even if you can avoid the microbe issues that plague ULSD, if you’re like most heating oil users, you may not have check in your tank for a number of years. And that makes you’ve got x years worth of sludge sitting in the bottom of that tank.
There’s no difference between the sludge that comes out of red diesel and the sludge that comes out of stored regular on-road diesel. They both represent lost heating value from that fuel. They both come from chain reactions in the fuel that make it unstable over time.
Can you burn off this sludge? Absolutely, if you can get back into the fuel. That’s where a good heating oil additive for red diesel comes in handy. A good one will help draw this sludge back into the red diesel over time and enable it to be burned along with the rest of the heating oil.
This kind of process isn't one that happens quickly. So it’s a great idea to treat the fuel at the start of the season to allow time for the red diesel sludge to be gradually removed. Your storage tank, oil guns, lines and furnace gradually become cleaner and function better. And a better functioning heating system can return real dollar savings back to you.
Other posts about Diesel:
- "Wow" Facts on Contaminated Diesel Fuel. Be Prepared.
- Diesel fuel degradation in storage - the signs
- Diesel fuel tank sludge during storage a rising concern
Image Credit: Gettingthat
This post was published on July 28, 2015 and was updated on April 15, 2021.