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Has your car got the ‘Blues’?
AdBlue is quietly reshaping how diesel engines meet emission standards — but for many Kenyan motorists, it’s an unfamiliar system with big consequences if ignored.
I recently purchased a used Toyota Prado, and the first warning light message it has sent me is “AdBlue”. What on earth does that mean? Seth
It means another potential benefit and another hassle. AdBlue is the latest “additive” for diesel-engined vehicles to help “purify” their exhaust emissions – by turning harmful nitrous oxides (NOx) into harmless nitrogen and water vapour.
It does not go into the fuel itself; it is injected into the exhaust system after combustion, so you have to keep a separate AdBlue tank topped up about as often as you change the oil.
No problem. But, to comply with the latest exhaust emission standards, the car won’t start if the AdBlue tank is empty. There is a dashboard warning light system that reminds you when a refill is on the horizon, and with increasing frequency when replenishment is urgent.
In some designs ECU can also start to limit engine performance as a more insistent wake-up call. That is more than just helpful, because if the AdBlue tank reaches empty, the car will still run normally until you turn off the engine. Then, by deliberate and compulsory design, it won’t start again! Good to carry some spare AdBlue in the toolbox if your vehicle uses that system.
AdBlue is made of a mixture of urea (abundant in animal urine and used as a fertiliser) and deionised water (as added to car batteries). It is the latest advance in Selective Catalytic Reduction (SCR) technology (used by modern trucks) designed to achieve the latest Euro 6 (US Tier 4) standard on exhaust emission purity.
Without AdBlue, the engine would not pass that test so, to qualify, the vehicle must have a system to inject AdBlue, and not just hope you use it; it must ensure you do.
So, its computerised management systems “read” the AdBlue level, report its condition, and are programmed to disarm the engine starter function if the AdBlue tank is empty.
The system is already operating in large numbers of diesel vehicles worldwide, especially trucks, and (unless/until another solution is invented) it is likely become increasingly common...even universal...on all diesel vehicles. Kenya’s transport fleet operators already know the score.
Some Kenyan motorists have started to encounter the challenge for the first time, and many more might follow.
Kenya does not yet insist on Euro 6 emission standards, but we get the majority of our mitumba cars from countries that do, so we will be getting more and more.... The most common so far is selected models of a brand that is “always in front” – so it makes sense for them to be more fastidious about what gas comes out of their back end.
It is technically possible to alter or disable the no-restart system, but that would be unethical (environmentally), could be deemed illegal where Euro 6 is a condition of licensing, and might well interfere with your warranty and insurance cover. Computerised sensors also have ways of knowing if AdBlue is substituted with another liquid.
While refilling the AdBlue tank is an inconvenience (especially if AdBlue is not available where you happen to be), it doesn’t have to be done often.
One tankful of AdBlue will last most passenger cars at least 6000 kms, and sometimes more than 10,000, depending on the size of tank fitted to your SCR vehicle and its fuel consumption. Filling the tank could/should be a regular item during routine service.
Because AdBlue consumption is related to fuel consumption and big trucks have been the first users, AdBlue is commonly retailed in 20-litre plastic jerry cans, and they have in-board tank sizes to match. The price is not exorbitant...about twice as much per litre as the fuel itself but consumed in much smaller quantities.
Given increasing pressure to reduce toxic emissions, the AdBlue system is likely to spread and grow, and perhaps all diesel-engined vehicle designers will adopt it. Then AdBlue retailed in an appropriate range of pot sizes and systems to assure availability – everywhere – will develop.
Overall, AdBlue it is probably a good thing. Nox is not. But as with so many other advances, the eco gains at the end of your exhaust pipe are probably eroded somewhat by the negative costs/emissions of harvesting, processing, packaging, distributing and utilising the cure product.
By the time every motorist knows what AdBlue is, we will have a better perspective on that.
Also, for perspective, for every tankful of fuel your car burns, it swallows more than a tonne of air (more than half of which is nitrogen). As a rough rule-of-thumb, a tonne of air at normal atmospheric pressure occupies about 1,000,000 litres of “outdoor” space.
Enough to fill a house! And that is roughly what comes out of the tailpipe of one (!) car while consuming one (!) tankful of fuel. A billion cars are doing that worldwide...all the time. So don’t be too hasty to sniff at anything that reduces NOx.
