Particle Filter Additive Service

Eolys fluid (also called DPF additive or PATS fluid) typically lasts between 70,000 and 120,000 miles, depending on the vehicle make, model, and driving style.

Most cars have a separate Eolys tank that slowly doses small amounts of fluid into the fuel when you refuel. Once the fluid runs low, your vehicle will usually display a warning light or message.

It’s important to refill Eolys fluid on time, as running the system empty can prevent the DPF from regenerating properly, leading to blockages, loss of power, and costly repairs.

If the Eolys runs out then for a short while nothing untoward will happen as the FAP fills up with particulates. The problem will come when regeneration is initiated. The Eolys is there to reduce the temperature at which regeneration can take place so the probability is that the particulates will not burn off. This means that in very short order the FAP will become blocked and the engine just won’t work as the exhaust gasses can’t get through properly.

There will probably be lots of warning lights and messages on the dash whilst all this is happening so you won’t be unaware of it!

If the fluid is low or runs empty, your DPF won’t be able to regenerate properly. This can lead to:

• DPF warning lights

• Loss of engine power

• Higher fuel consumption

• Costly DPF blockages or damage

Refilling the fluid at the correct intervals avoids expensive repairs and keeps your DPF system working as it should.

Each model varies on amount required every manufacture has a maximum set for the tank.

A full tank of eolys additive should last around 70,000 miles.

Eolys fluid is only mildly toxic after it has done its job in the exhaust but this is being measured in parts per million. Actual contact of Eolys fluid with the skin (or any other body part) where the concentration will be higher is to be avoided.

Eolys fluid can be brought in kits or 1-5litre bottles and prices vary.

Eloy fluid has a separate tank mainly underneath the vehicle access can be tricky, programming and data reset is required once complete.

PATS fluid (sometimes called DPF additive fluid, Eolys fluid, or PAT fluid) is a special liquid used in certain diesel vehicles to help the Diesel Particulate Filter (DPF) regenerate more effectively.

When you refuel, a small amount of this fluid is automatically added to the diesel tank. The fluid lowers the burning temperature of soot particles, making it easier for the DPF to burn them off during normal driving.

Over time, the PATS fluid tank runs low and needs refilling. If the system runs empty, the DPF will struggle to regenerate, often causing warning lights, reduced performance, or even filter blockages.