The exhaust fluid is often used in low emission diesel models equipped with SCR technology and is continuously sprayed into the exhaust gas, upstream of the catalytic converter to assist in the breakdown of harmful nitrogen oxides (NOx). The problem is, if the AdBlue fluid runs out, the vehicle won’t start.

To take the confusion out of AdBlue and its warning light system, Venson has issued guidance on what to do.

Gil Kelly, operations director of Venson Automotive Solutions Ltd, explained: ‘If a car is equipped with SCR technology it will have an AdBlue tank. The location of the tank varies across manufacturers and from model to model, but is often close to the diesel tank or in the boot, under the carpet, or in the engine compartment. It can usually by identified by a blue cover. 

‘Manufacturers will typically top up the tank at time of service, but consumption of AdBlue can vary enormously according to vehicle type and model, vehicle load, environmental conditions, driving requirements and driving style. For instance, a vehicle may use more fluid on mountain roads or towing or if a driver accelerates a lot, just like with fuel. Additionally, with many of today’s diesel vehicles having variable servicing intervals, fleet managers need to encourage drivers to keep a watchful eye on tank levels to ensure their vehicle will start.

‘To further complicate matters, AdBlue tank capacities vary from model to model, with motor manufacturers calculating the average miles a tank of AdBlue will last. The more economically a car is driven, the less AdBlue will be used. Vehicles using AdBlue are equipped with special dashboard warning lights, but again the message displayed varies across manufacturers, despite everyone agreeing that if the tank is allowed to run dry, the vehicle will not start. 

‘Adding to the confusion, the price of AdBlue varies considerably. It can be bought at retail outlets, dealerships or service stations, with some manufacturers providing AdBlue free of charge, if supplied through one of their dealerships.’

He added: ‘The advice we’re giving our fleet customers is to have drivers call their dedicated Venson driver hotline number, as soon as the warning light appears, so we can schedule a visit to a dealer, allowing the AdBlue tank to be refilled without delay. This will help to ensure the vehicle is kept on the road without incurring unnecessary costs.’