Diesel Exhaust Fluid (also known as AUS 32, or generically as urea) is a solution of solid urea dissolved in deionized water to produce a concentration that is 32.5% urea and 67.5% deionized water.
How does DEF work?
Controlled amounts of the DEF solution are injected into the engine exhaust stream prior to the SCR catalyst. The temperature of the exhaust converts the urea in the DEF to ammonia. The ammonia and NOx in diesel exhaust react in the presence of the SCR catalyst to convert the NOx into nitrogen (N2) and water (H2O).
Currently, Cat branded Diesel Exhaust Fluid is not available for purchase in New Zealand. As an alternative, Gough Cat can supply you with AdBlue® for the same superior performance and results.