McKeown Petroleum has led the charge as the first oil company in New Zealand to supply an SCR (Selective Catalytic Reduction) Fluid or DEF (Diesel Emission Fluid) as it is more commonly known as in New Zealand, to their customers and general public from retail dispensing facilities in Kumara, Christchurch, Twizel, Methven, Gore and Alma.

McKeown Petroleum went to a great deal of effort to research the best and most reliable SCR supply partner in New Zealand – a company who could meet the highest standards of product quality, maintain a consistent supply to our company and provide a competitive price to our customers. There was only one company that ticked all our boxes and that was Balance Agri, well known in New Zealand for their fertilizers and on farm products. Their SCR product brand is GoClear which is 100% manufactured here in New Zealand to the ISO22241 standards required by all OEM’s.

For anyone not purchasing from McKeown Petroleums  selected CardFuel 24/7 facilities with GoClear  SCR additive on them McKeown Petroleum can also supply your requirements in 1000 litre IBC’s, 200 litre drums and 20 litre containers by contacting us on 0800 800 908 or emailing us on sales@mckeown.co.nz

The following provides a brief history on what brought SCR Technology about, what it does and why vehicles manufactured after 2010 will be required to use it.

The Why’s and Where To’s of SCR Technology:

Since the passing of the Clean Air Act in the 1970s, the Environmental Protection Agency (EPA) has regulated emissions of NOx, particulate matter and other pollutants from road vehicles, electric utilities, and off-road equipment.

Heavy-duty trucks:
The EPA adopted emissions standards for heavy-duty vehicles in 2001 which would govern models manufactured from 2007 onwards and required manufacturers to reduce particle matter emissions to 0.01 g/bhp-hr and NOx emissions to 0.20 g/bhp-hr. Between 2007 and 2009 there was a phase-in period for which allowed NOx emissions of 1.2 g/bhp-hr, but from 2010 all medium and heavy duty diesel vehicles have had to meet the standards. Manufacturers that exceeded requirements before 2010 such as Cummins and Navistar are allowed NOx emissions up to 0.5 g/bhp-hr under a bank and trade system.

Off-road vehicles:
In 2004 the EPA issued its final program to reduce emissions from off-road diesel engines, to be phased-in from 2008 to 2015. The Tier 4 off-road rule established new emissions standards and test procedures and led to the implementation of Selective Catalytic Reduction(SCR) technology by a number of manufacturers.

The exhaust standards require emissions of particle matter and NOx be further reduced by about 90% from Tier 1-3 standards. Beginning in 2008, the new Tier 4 engine standards for five power categories of engines from under 25 hp to above 750 hp have been phased in.

Cars, pickup trucks and SUVs:
The Clean Air Act first set out emissions rules for diesel cars as part of a set of amendments in 1990. Tier 2 standards were adopted in December 1999, with an implementation schedule of 2004 to 2009. Under Tier 2 federal regulations emissions limits were made more stringent and the same emission standards were applied to all non-commercial vehicles under 10,000 kg’s and commercial vehicles under 8,500 kg’s.

This meant passenger cars, pickup trucks and SUVs all become subject to the same rules and, because the standards are expressed in terms of emissions per kilometre, larger vehicles require more advanced engine and after treatment technology than smaller vehicles.

Tier 2 limits the average NOx emissions of all vehicles sold by a manufacturer to 0.07 g/kilometre. The Environmental Protection Agency allows emissions from vehicles which are under this limit to be offset with those above it in a complex system which divides vehicles into different ‘Bins’ based on whether they are above or below this limit.

ISO standard:
The production, handling and transportation of Diesel Exhaust Fluid (DEF) is governed by the ISO 22241 standards and the key points are:

  • Diesel Exhaust Fluid (DEF) must have a urea concentration of 32.5% by weight. This concentration was chosen because it is has the lowest freezing temperature, 12°F.
  • The maximum level of impurities such as calcium and various metals such as iron, copper, zinc and aluminum are clearly specified. These limits are very low, to ensure reliable operation of the SCR system.
  • This definition excludes the use of urea grades used in agriculture, and requires water purified by distillation or deionization or similar.
  • Materials which are safe for the storage and handling of Diesel Exhaust Fluid (DEF) – stainless steel, polyehylene and fibreglass are compatible with GoClear.
  • With any other materials refer back to McKeown’s for further advice.

Frequently Asked Questions

What is Diesel Exhaust Fluid (DEF)?

DEF is a non-toxic solution of 32.5% urea in de-ionized water. This fluid is sprayed into the exhaust stream of diesel vehicles to cause a chemical reaction and break down dangerous NOx emissions into harmless nitrogen and water.

This system is called Selective Catalytic Reduction (SCR) and can be found on almost all 2010 model year onwards, heavy duty trucks and many diesel pickups and SUVs.

DEF is not a fuel additive and never comes into contact with diesel. It is stored in a separate tank on the vehicle or equipment, typically with a blue filler cap.

Why are manufacturers using Selective Catalytic Reduction (SCR) to meet the 2010 guidelines?
The Environmental Protection Agency’s latest emissions rules for diesel vehicles of all sizes are some of the most stringent emission standards in the world. The majority of light and heavy-duty diesel vehicle manufacturers came to the conclusion that the only way to meet these rules without compromising engine performance and fuel efficiency is SCR.

What fuel saving can I expect from a truck equipped with Selective Catalytic Reduction (SCR) technology?
Because SCR is an emissions control technology installed in the exhaust, manufacturers are able to tune engines to boost performance and achieve large fuel savings in their 2010 and later model trucks. The extent of these savings will vary, but fleet experience with heavy 2010 heavy duty trucks suggests fuel savings of around 5% compared to 2007 models with similar engine specifications. PACCAR, Daimler and Cummins all use this figure in their 2010 model specs. Reports from customers using off-road machines with SCR are reporting fuel savings of 5% and higher.

Diesel Exhaust Fluid (DEF) consumption is measured as a ratio of diesel fuel, sometimes called the “dosing rate”. A good starting point for this ratio is 3% and this figure has been widely used by heavy-duty truck manufacturers. This means that if your truck has a fuel efficiency of six miles per gallon it will use 1.5 gallons of DEF every 300 miles.

Feedback from a number of fleets, including Penske Truck Leasing, suggests that the dosing rate is slightly lower than originally predicted by manufacturers, at around 2%.

What is the difference between agricultural urea and the urea used in Diesel Exhaust Fluid (DEF)?
DEF uses automotive grade urea which has a much higher purity than its agricultural counterpart. Using a lower quality urea will cause degradation of the Selective Catalytic Reduction (SCR) system, eventually causing the truck to break down. In the short-term it may also cause the sensors to believe the truck’s DEF tank is empty and prompt a derating event, which reduces engine power and eventually prevents the engine from restarting.

What will happen if my truck runs out of Diesel Exhaust Fluid (DEF)?
The EPA requires vehicle manufacturers to put measures in place to ensure that vehicles cannot run without DEF. Most manufacturers have approached this in a similar way. Before a truck’s DEF tank runs empty the driver is given a series of alerts on their dashboard displays (much the same way as if they were running low on diesel). Generally speaking, when the DEF tank level drops below 10% an amber warning lamp will come on, at 5% this lamp starts flashing and below 2.5% a solid amber warning light is displayed.

If the truck is allowed to run out of DEF completely, the engine’s power is reduced. This generally follows the next intentional key-off, when vehicle speed will be limited to 5 mph and a solid red warning will be displayed.

What is the shelf life of Diesel Exhaust Fluid (DEF)?
DEF has a shelf life of two years. However, this can be reduced if the fluid is exposed to direct sunlight for a long time or if the temperature of the DEF remains above 25°C for sustained periods. All DEF packaging should be labelled with the expiry date.

Is Diesel Exhaust Fluid (DEF) corrosive?
DEF is not toxic, harmful or dangerous. In fact, of all the fluids used in a truck like diesel, engine oil, brake fluid, antifreeze and windscreen wash, DEF is the least hazardous. However, DEF is corrosive for some metals such as carbon steel, aluminium, copper and zinc. Your DEF supplier can advise you further. ISO 22241 provides a list of materials that are recommended and not recommended, but makes it clear that neither list is exhaustive.

Do I need to wear protective clothing when filling up the DEF tank?
No. If you do spill any DEF on your clothing, simply rinse it off with water or wipe it away.

What should I do if a spill DEF?
If you spill a small amount of DEF, it can be washed away with water or wiped up. If you leave it to dry it will turn into white crystals. These can be washed away with water. If you spill a large amount of DEF then contact your DEF supplier for advice. Remember that urea is widely used as a fertilizer so small amounts of DEF can be disposed of by diluting with water and spraying on your lawn or garden.

If I switch Diesel Exhaust Fluid (DEF) suppliers, what should I do with the fluid which remains in bulk storage tanks and do I need to have them cleaned out?
No, simply run the tank as empty as possible before refilling. DEF is a pure chemical, so your bulk storage tank never needs to be cleaned out unless it is contaminated by another substance.

How does Selective Catalytic Reduction (SCR) affect a vehicle’s performance?
Since the introduction of environmental legislation truck manufacturers have battled to reduce emissions while maintaining and improving engine torque. Selective Catalytic Reduction (SCR) is an after treatment technology, meaning it deals with emissions without using in-engine controls like Exhaust Gas Recirculation (EGR), this has allowed manufacturers to tune engines, improving fuel efficiency and increasing torque.

Where can I buy Diesel Exhaust Fluid (DEF)?
You can view locations on this website, contact McKeown Petroleum on 0800 800 908 or email sales@mckeown.co.nz. McKeown Petroleum will provide listings of CardFuel 24/7 pump purchase facilities and retail locations for DEF in 1,000 litre IBC’s, 200 litre drums and 20 litre containers so give us a call.

Is there any danger of filling the Diesel Exhaust Fluid (DEF) tank with diesel and what problems will it cause?
The filler necks of DEF tanks are smaller than the nozzle used to dispense diesel, making it difficult to fill the DEF tank with diesel fuel. The DEF tank cap is ‘normally’ blue and clearly marked ‘Diesel Exhaust Fluid’ with the accompanying ISO standard number or other identifying marks.

There have been a small number of instances where this has happened although it’s difficult to imagine how. In these cases the SCR system had to be drained and no permanent damage was done to the SCR catalysts. If you do accidently fill your DEF tank with diesel, then contact your dealer immediately. Diesel is less dense than DEF and will float on top of the DEF in the tank but even small amounts of diesel can damage your SCR system. So we recommend that you contact your dealer immediately and do not drive the vehicle.

A large part of Diesel Exhaust Fluid (DEF) is de-ionized water do I have to worry about the tank or other parts of the Selective Catalytic Reduction (SCR) system freezing?
DEF freezes into a crystalline slush at -10°C and should not be kept at temperatures above 30°C. Manufacturers use a variety of heating methods to thaw frozen DEF tanks, including in-tank heating elements.

While the thawing process is taking place the vehicle’s performance will not be affected (although it may marginally reduce the amount of DEF that is used as a cold engine produces a low level of NOx emissions). In some cases the DEF supply tubes are also heated to prevent freezing, or these tubes are emptied once the engine is turned off.

In short, there is no reason to be concerned about using your SCR truck in cold weather, even in the coldest weather.

Are there any heavy-duty truck manufacturers that don’t use Selective Catalytic Reduction (SCR) technology to meet 2010 regulations?
Navistar is the only heavy-duty truck manufacturer not to use SCR to meet EPA 2010 emission standards. Its 2010 models use a combination of Exhaust Gas Recirculation (EGR) and emissions credits earned by meeting new legislation ahead of schedule.

This means that Navistar trucks are allowed to emit NOx at levels above those specified in the 2010 rules up to a limit of 0.5 g/bh-hr.

When was Selective Catalytic Reduction (SCR) technology first used?
SCR technology was first patented in 1957 and has been used for many years to reduce NOx emissions from coal-fired power plants. The technology was first used in vehicles by Nissan Diesel in Japan in 2004 to meet emissions standards that were the strictest in the world at that time. Since then SCR has been widely implemented on diesel vehicles and by the end of 2010 more than 1 million commercial vehicles were equipped with SCR emissions control technology in Europe alone.

In Summary:
If you still have any unanswered questions regarding this product or you wish to order your supply of GoClear, SCR please contact McKeown Petroleum on 0800 800 908, email sales@mckeown.co.nz or from the contact page of this website

Contact Details:

Waterfront Road
PO Box 124

Freephone: 0800 800 908
Direct Dial: 03 433 1022
Fax: 03 434 7978
Email:  sales@mckeown.co.nz