“Having a 3.3-liter engine means we want to be on the safe side for torque and power,” Kunz said adding the Mazda believes the forthcoming diesel will offer fuel economy figures comparable with a turbocharged four-cylinder engine with the same power output.
To achieve this Kunz said the diesel needs to have excellent combustion efficiency, so the more of the heat it produces is translated into power and less heat is lost to the cooling system.
“To get low NOx emissions we need low combustion temperatures,” Kunz said. “Having a bigger engine keeps temperatures lower, which is good both for reducing the heat loss and for cutting the raw NOx emissions. This in turn will enable us to have a simpler after-treatment system.”
Kunz said the diesel will include a selective catalytic reduction (SCR) system “to show the customers that we are making ever effort to reduce NOx.” The SCR, which converts NOx with the aid of a catalyst into diatomic nitrogen and water, will be smaller and require less frequent urea refills by the customer, Kunz said.
Kunz said Mazda plans to offer the CX-60 diesel to its sales companies throughout Europe, with the possible exception of Norway, where electric cars already account for the vast majority of car sales.