|Mazda CX-7 equipped with a MZR-CD 2.2-liter clean diesel engine (European specifications). Click to enlarge.|
Mazda Motor Corporation will exhibit freshened CX-7 SUVs with European specifications at the 63rd Frankfurt Motor Show, which will be held from 15-27 September. Newly added to the updated CX-7 lineup—and to be exhibited at the Frankfurt Show—is a version powered by Mazda’s MZR-CD 2.2 liter diesel engine mated to a selective catalytic reduction (SCR) system. (Earlier post.)
SCR systems substantially reduce NOx emissions, which helps the diesel CX-7 to comply with Euro5 emissions regulations. The diesel CX-7 will be launched in Europe in October 2009, with Australian sales following in November.
|Urea SCR system diagram. Click to enlarge.|
Mazda’s MZR-CD 2.2L turbodiesel engine produces low volumes of engine-out NOx, which means that the SCR system needs to remove less NOx in post processing, resulting in a reduced amount of urea required for NOx reduction. Mazda’s SCR system sprays AdBlue aqueous urea directly into the exhaust flow in front of the catalytic converter, with conversion of approximately of 40% of NOx into nitrogen.
By reducing the size and weight of the system components, which include an AdBlue storage tank fitted under the luggage area, Mazda is the first Japanese automaker to successfully equip a passenger vehicle with an SCR system.
Even with the added components, the diesel powered CX-7 offers the same 455 liters of luggage space as gasoline engine models. Additionally, Mazda’s SCR system was designed to minimize consumption of AdBlue, enabling the diesel CX-7 to run for 20,000 kilometers (12,427 miles) between refills under normal driving conditions.