Mazda's new CX-7 four-wheel-drive uses a urine-like solution to cut its tailpipe emissions, indicates report.
According to a report by Fairfax Digital, the compound, called AdBlue, is a mixture of roughly one-third pure urea and two-thirds demineralized water.
It is already widely used in the trucking industry in Europe and Australia and is common in diesel cars in Europe, but Mazda is the first to use the technology on a passenger vehicle in Australia.
The technology, called selective catalyst reduction, involves injecting the urea-based liquid into the car's exhaust system to turn NOx emissions into harmless nitrogen and water.
The car also has a particulate filter to reduce the amount of soot emitted by the vehicle.
To guard against forgetful drivers not filling its AdBlue tank, the Mazda CX-7 diesel will cut its maximum speed if the level of AdBlue falls below a certain level.
The car will not start if the AdBlue tank is empty.
The 15.5-litre tank is mounted under the rear-floor of the CX-7 and Mazda recommends the task is undertaken by an authorized dealer as part of scheduled servicing.
A gauge and warning lamp warn the driver as the level drops.
The AdBlue tank requires refilling every 20,000 km and costs about 140 dollars a refill, which works out to roughly 7 dollars per 1000 km.
The new diesel Mazda continues a trend by car makers to reduce CO2 emissions by introducing smaller, less powerful petrol engines and diesel powerplants.