How to Spot Fuel Quality Issues

Watch for these signs of poor fuel quality:

  • Filters are plugging up faster than normal
  • A spike in injector replacements
  • More frequent regens in your exhaust system
  • Positive oil test results for fuel dilution
  • Reduced engine power or rising fuel consumption
  • Hard starting followed by rough idling

If you're experiencing symptoms, it's probably time to take a closer look at your bulk fuel setup.

What You Can Do to Protect Your Fleet

Fuel doesn’t always arrive clean. In fact, most diesel picks up contaminants during transportation and transfer through multiple storage tanks. According to Donaldson's experts, here’s how to enhance your fuel cleanliness:

1. Improve your Housekeeping

  • Inspect and clean fuel tanks regularly
  • Remove sludge, sediment, and water
  • Schedule major maintenance events

2. Install Filtration at every Practical Stage

  • At delivery: Use a single-pass filtration system to capture contaminants before they enter your tank
  • In storage: Install high-capacity regenerative TRAP™ breathers to minimise dust and moisture ingress
  • At dispense: Use high-efficiency and water-absorbing filters in series to clean and dry fuel before it reaches your on-vehicle tanks.
Thermally Reactive Advance Protection (TRAP) breather Thermally Reactive Advance Protection (TRAP) breather

What About Truck Stop Fuel?

Don’t assume fuel from retail stops is clean enough for modern engines. Poorly maintained low-turnover sites with aged infrastructure may present greater risks. Have your maintenance team consult with your fuel suppliers about their cleanliness standards and expectations.

Be cautious using additional fuel additives, simply because more may not be better. Consult your engine OEM, fuel supplier and filtration provider before adding additional products to your fuel.

Filtration manifold system on the inlet Filtration manifold system on the inlet

The Bottom Line: Clean Fuel means less Downtime

Fuel-related failures are a growing concern across industries. Taking proactive steps to keep diesel clean and dry helps:

  • Extend maintenance intervals
  • Reduce unplanned downtime
  • Lowers the total cost of ownership

One of the best things you can do for your equipment is to ensure the fuel it's burning is as clean and dry as possible.

The pump is the most critical place to filter fuel The pump is the most critical place to filter fuel