How AdBlue® can reduce your car’s harmful emissions

Diesel and petrol engines both produce dangerous emissions that impact on the environment but there is a way you can drastically reduce the harmful gasses your diesel gives off as well as gaining the optimum performance from your vehicle.

Euro 6 Standards

Since 2005, legislation on diesel vehicles in the UK & Ireland and in the rest of Europe demands a drastic reduction of NOx emissions meaning vehicle manufacturers had to re-think the exhaust system on their vehicles.

These regulations, known as Euro 6, set different standards for diesel and petrol cars. For diesel cars, the new cap on the permitted level of NOx emissions has lowered to 80 mg/km, a dramatic drop from the 180 mg/km level required to meet the previous Euro 5 standards. The limit for NOx from petrol cars remains at 60 mg/km, the same as for the Euro 5 standard.

Harmful Emissions

Diesel engines release emissions that impact on the environment. In recent years, significant investment by the automotive industry has seen the environmental impacts of engines using either fuel reduced or advanced selective catalyst reduction (SCR) exhaust after treatment, which ensures cars meet EU6 NOx standards.

What is Catalytic Reduction?

Selective Catalytic Reduction is an active exhaust gas after-treatment system which converts NOx into less harmful gases and water. Most major vehicle manufacturers have adopted the technology to significantly reduce emissions and comply with the strict new emissions standards.

How does DEF (Adblue) work?

A special Diesel Exhaust Fluid (DEF), often referred to as AdBlue®, makes this possible. DEF is an aqueous urea solution (32.5% urea and 67.5% deionized water) that is injected into the exhaust flow. This causes ammonia to be produced, which breaks down up to 98% of NOx into nitrogen and water.

About AdBlue®

AdBlue® converts harmful NOx from your diesel vehicle exhaust into harmless nitrogen and steam, therefore considerably reducing the emissions of nitrogen oxides (NOx) that are a major source of atmospheric pollution and that lead to smog in urban centres.

32.5% urea and 67.5 deionized water AdBlue consumption varies depending on the particular after-treatment system of the exhaust gasses, but also on driving style and driving conditions. A vehicle that is being driven hard or a car that’s only in start-stop traffic conditions might have a higher AdBlue consumption than one that gets a good mix of city and highway miles.

AdBlue is not toxic and is odorless. It must be stored and transported with care and if you get any on your skin, rinse thoroughly as it can be a mild irritant. 

How to use AdBlue®

AdBlue is very easy to use and is a harmless substance.

It is not a fuel, nor a fuel additive but a high purity urea solution that must be used in a dedicated tank (DO NOT ADD IT DIRECTLY INTO YOUR DIESEL TANK) on your vehicle and can be refilled as and when required.

For optimum performance of your vehicle never add anything to your AdBlue as even the addition of water could damage the catalyst in your SCR system.

Be careful when filling the tank yourself, as AdBlue can act as a mild corrosive. Read the safety advice on the bottle carefully before attempting to refill. Some AdBlue bottles have a filler tank adapter, which screws onto the filler neck of the AdBlue tank underneath the screw cap. Some AdBlue filler caps on older models will require a tool to undo the cap. This is located in the boot – please see your vehicle owner’s manual for more information.

How will I know if the system needs topping-up?

For example; On all Volkswagens a series of warnings will be given via the driver information system, accompanied by advice/messages.

The first message is displayed when the remaining range is approximately 1,500 miles, and is repeated every 62 miles until the range reaches 1,000 miles, at which point the warning turns amber. This warning is repeated every 31 miles and is accompanied by an audible tone. If these warnings are not acted upon, the warning turns red; once this happens the car will not restart once the ignition is turned off. This is not a fault, but a required feature of the system. If this stage is reached the system will need a full top-up before the car can be restarted. Further information is available in your vehicle owner's handbook.