Contact Powerblanket’s friendly, knowledgeable staff today with any questions you have about protecting your DEF. You can easily reach us at 866.945.4203. The Powerblanket DEF tank heater is the most efficient and effective way to heat and store diesel exhaust fluid. Explore DEF Storage Heaters. On average, gasoline will last and can be stored for about 8 months in a sealed container and 3 to 6 months in your car’s tank. Diesel fuel is rated for twice the amount of time, ranging anywhere from 6 to 12 months in the tank. ExxonMobil suggests that you can keep gasoline in a sealed container for about six months. Maximum Storage Time. The maximum storage time for diesel fuel is around 18-24 months, although this can vary depending on the specific type of diesel fuel and the storage conditions. After this period, the fuel may start to degrade, leading to sedimentation, sludge buildup, and a decrease in lubricating properties. How to Recondition Old Diesel Fuel. Pour fifty gallons of old diesel fuel into the fifty gallon drum. Measure 3.125 oz. of PRD-D or 280 oz. Add the fuel re-conditioner directly to the stored fuel storage if possible. Allow the old diesel to sit for a day or two. Use the fuel as if it were fresh from the pump. As a general rule, open diesel fuel can last up to 1 month. If you have stored the diesel in a sealed container indoors or it is in a vehicle tank, it will last 6 months with no treatment. If you have treated the fuel with biocides and stabilizers, it will last 12 months. Longer than 12 months, it will require more maintenance. Biodiesel is a clean-burning alternative fuel for diesel engines made from animal fats or vegetable oils, such as soybean oil. Pure biodiesel (B-100) contains no petroleum, is biodegradable and nontoxic. Pure biodiesel is often blended with petroleum diesel to create biodiesel blends, such as B-2 or B-5; this designation indicates a 2% or 5% 1. Remove any excess water sitting in the fuel tank. 2. Change fuel filters that have built up contamination. 3. Use a mobile fuel polishing system to circulate fuel out of the tank, filter the fuel, and return it. 4. Use a biocide or chemicals that kill bacteria and other contaminants. For engine equipment used regularly, add Sea Foam to a tank of fuel every 3 months or sooner. For All Other Engines and Fuel Tanks (not used regularly): Add Sea Foam to every tank of fuel. Most engine manufacturers agree that unprotected fuel will degrade within 30 days. Additional: Normal fuel tanks. The normal fuel tanks are used only for the storage of fuel oil. They are usually located toward the extremities of the boat rather than close to amidships. They vary in size, but normally have capacities of from 10,000 to 20,000 gallons each. Most modern submarines have four of these tanks. Diesel fuel should last a long time if it is kept clean and dry unlike E10 gasoline which actually tends to trap water in it over time. Age of the fuel should not be an issue if the tank (s) are kept clean and dry and the fuel source is also clean. 01-08-2009, 00:30. # 4. YsBZ2.