Full explanation
SCR consists of: (1) a 40–75 L on-tractor AdBlue tank (ISO 22241), (2) a dosing injector upstream of the SCR catalyst, (3) the SCR catalyst itself (vanadium-zeolite or FeZSM-5), (4) ECU-controlled injection with upstream and downstream NOx sensors. AdBlue consumption is 3–7% of diesel use (100 L of diesel = 3–7 L of AdBlue). Ukrainian pain points: (1) counterfeit AdBlue in small packs — technical-grade urea without ISO 22241 crystallizes in the injector and destroys the catalyst (repair USD 4,000–12,000), (2) long storage >12 months causes urea hydrolysis and efficacy loss, (3) the tank freezes below −11°C and requires heating (standard on Stage V). SCR-emulators are widely sold on AliExpress/OLX for USD 40–120. They are illegal, with UAH 40–170k fines under Ukraine's Administrative Offences Code. From 2026 the EU will check at the CBAM border; SCR-delete detection triggers shipment return.