Poor quality diesel will affect the overall performance and composition of your engine. Over time these particles will start to build up inside the system and lead to corrosion. This will eventually result in damage to not only your filters and injectors, but other crucial components like pumps too.
You'll get lower fuel efficiency. Hesitation upon acceleration and rough idling. You'll also get higher levels of certain kinds of emissions, though those will be caught by the emissions control system. So the hesitation, idling and reduced fuel mileage would be the signs you'd be most likely to notice.
Low power from the engine. Reduced engine RPM. Increased fuel consumption. Poor cycle times or low speed.
As for diesel, it can remain usable for between six and 12 months before becoming 'gummy' which, if used, can clog up filters and cause you issues with your engine.
Dirty fuel can cause premature failure in equipment of any age.
Diesel fuel can only be stored from 6 to 12 months on average — sometimes longer under the best conditions. Generally, to prolong the life of the quality of stored diesel fuel, it should be: Kept cool at around 70 degrees Fahrenheit; Treated with biocides and stabilizers.
The ideal conditions for storing diesel fuel include keeping fuel dry and at a cool temperature (below 70 degrees Fahrenheit). Such conditions ensure storage life between six to twelve months. To extend fuel life beyond twelve months, fuel stabilizers are required.
By recirculating the fuel in the tank through a filter it will break up and remove the sludge and water in the tank. All diesel fuel can be cleaned and made back into good useable fuel. Do not use fuel that is not clear in color.
Darkened Fuel
Normal undyed diesel fuel is a beautiful amber-green color. The same fuel which has started to degrade will darken. This is because heavier components of the fuel blend are no longer dissolved in the fuel, but are coming out of solution and floating freely in the fuel.
IF it's a common on-road diesel (which will have 3-5% biodiesel content in it) and if it's reasonably well taken care of (water removed monthly, fuel is monitored for microbes), you would expect to get 18-24 months out of it before you would expect to start seeing issues. Sometimes 12-18 months.
Defining Diesel Fuel Quality
The main way to measure fuel quality is by determining its cetane number, which highlights the speed and efficiency of combustion. Other tests measure stability and contamination levels, which also affect how well it functions.
Most Common Fuel Contaminants: Sludge and Particulates
Sludge buildup happens because diesel fuel forms heavy polymers that drop out and collect at the bottom of the tank, resulting in a sludge buildup in the storage tank itself.
K-100 is an all-encompassing, universal gasoline and diesel additive that cleans, eliminates water, lubricates, reduces emissions, and stabilizes old fuel as well as boosts octane rating.
So, when water gets into your fuel, it freezes and causes problems like power loss, plugged filters, fuel part corrosion, and injector wear. That's why you notice more problems in the winter if there's water.
' In reality, there is no expiration date on diesel per se, but the performance of your diesel fuel is affected the longer you store it. In fact, storing diesel without properly treating it can lead to all kinds of issues, not only for the fuelitself, but for any vehicle you decide to put the fuel in later.
Depending on the age and contamination level of old diesel fuel, CommTank's fuel polishing service can typically rejuvenate and bring it back to ASTM standard specifications, so it will work like new.
According to most refiners, diesel has an average shelf life of 12 months if stored at a temperature below 20°C (68°F).
It's up to you if you want to take that risk, but the safest thing to do is not to drive the car. If you think you have phase-separated fuel in your gas tank (i.e. you picked it up from somewhere else), the best solution is going to be to have it pumped out and replaced with fresh gas.
What Happens if I Delay Replacement? If your diesel fuel filter is clogged, it can result in poor fuel efficiency, shaky idling, difficultly starting, and sounds indicating your vehicle may stall because your engine's fuel injectors may not be getting enough fuel.
Age and condition – if the injectors are old or worn out, a clean may not be enough to restore performance and could do more damage. Severe clogging may mean they need to be replaced anyway. Costs – cleaning fuel injectors is cheaper than replacing them.