Q: I’ve been handling my diesel the same way for years. Why should I change now?
A: That’s a common question—and a fair one. While diesel fuel standards haven't changed much (aside from reducing the sulfur content), today's engines incorporate advanced technologies, meaning that they require cleaner fuel to perform reliably. Contaminated fuel that exceeds the World Wide Fuel Charters (WWFC) cleanliness expectations can cause serious damage that engine manufacturers don’t consider a warranty issue. To avoid costly, unwarranted repairs, it’s essential to ensure that your fuel is clean and dry.
Q: Isn’t it my supplier’s job to deliver clean diesel?
A: There is great variation in supplied fuels. Some parts of the world are serviced by fuel suppliers that take great pride in delivering incredibly clean fuel, while other regions have less stringent distribution methods and harsher environmental influences that impact fuel quality and cleanliness. Be wary of the term "clean diesel" as this may refer to ultra-low sulfur diesel (ULSD) or bio-diesel, meaning that these fuels are less harmful to the environment, - it doesn’t necessarily mean the fuel is free from harmful contaminants.
Q: How do I know if my diesel is clean enough?
A: The only way to be sure is by testing the fuel, which may prove a cost-effective option if you are managing a sizeable fleet.
- Use a certified oil analysis lab or perform a patch test in the field.
- Compare results using the ISO 4406 Cleanliness Code.
- Diesel fuel cannot be too clean, Donaldson recommends ISO 14/13/11 or better.
For your own personal vehicles, best practice is often to fuel only from high-turnover, well-maintained sites and to avoid fuelling your vehicle while a bulk tanker is offloading.
Q: My fuel filters keep plugging up. Should I switch brands?
A: Not necessarily. A clogged filter has done its job—protecting your engine from contaminants.
Older generation engines had a greater tolerance for contamination in the fuel supply, whereas modern engines require exceptionally clean fuel. To meet these stringent cleanliness expectations, modern, highly efficient fuel filters remove vast quantities of small contaminants from the fuel supply and potentially load and block faster than a traditional, coarser filter would. If your fuel supply is unchanged, you can anticipate that the fuel filter used on a modern vehicle may clog faster than the fuel filter used on an older engine.
If filters are plugging up quickly and you decide to change to an alternate brand of less efficient filter, the contamination that was being stopped is now passing to your engine, causing irreparable damage.
To fix the issue:
- Address the root cause rather than downgrading to less efficient filters.
- Rapid filter plugging can be the result of many complex factors, and it is recommended that you reach out to your fuel and filtration supplier for specific expert advice.
- Switching filter brands won’t help if the fuel supply is heavily contaminated.
Q: Why are my new injectors and fuel pumps failing so often?
A: Always start by talking to your equipment manufacturer. If fuel contamination is suspected, the next step would be to test the fuel supply, establishing the fuel's ISO4406 cleanliness level. It may prove as simple as:
- Installing a high-efficiency fuel filtration system at the dispensing point.
- If you fuel from multiple sites, installing an additional primary fuel filter on your vehicle
- Using the cleanest diesel possible may rectify your ongoing issues.
The added cost of highly efficient fuel filtration is often insignificant compared to the cost and inconvenience of hard part failures.
