Nissan Motor Co Ltd announced a new model of the "QX50" SUV in the "Infiniti" series of luxury cars Nov 29, 2017.
Nissan claims that the vehicle is equipped with the world's first VCR (variable compression ratio) engine. The engine is the "MR20DDT" 2.0L in-line four-cylinder direct-injection gasoline engine using a turbocharger.
Its compression ratio can be steplessly changed within the range from 14 to 8. Compression ratio is lowered to increase engine torque and increased to put priority on combustion efficiency. Its maximum output and maximum torque are 200kW and 380N·m, respectively.
Nissan's VCR consists of two mechanisms: (1) a mechanism for supporting the piston and (2) a motor mechanism for changing the position of the supporting mechanism. The former mechanism consists of (1) a con rod connected to the piston and (2) "Multi-Link" rotating mechanism connected to the crank shaft.
By connecting the lower end of the con rod and the rotating mechanism and changing the angle of the rotating mechanism, the location of the con rod is changed. The rotating mechanism is moved by a motor.
Introduction of ProPilot
This time, Nissan not only applied a new engine technology but also put energy into "intellectualization," for which the company has been making efforts. It employed "ProPilot," which helps drive on a single lane of expressway and is used for the "Leaf" electric vehicle (EV) and "Serena" minivan. With a monocular camera attached to the inside of the upper part of the windshield, the surrounding situations of the vehicle are monitored.
The ProPilot seems to be a conventional "Level 2" driving support system, which requires the driver to check the surrounding situations when the system is in operation. Also, if an accident occurs, the driver is liable for it.
Furthermore, Nissan fully remodeled the platform of the QX50. By applying 980MPa-class high-tensile steel plates, the company improved torsional rigidity by 23% while reducing mass, compared with the previous model. To improve driving performance, air resistance coefficient (cd value) was reduced by 6%, compared with the previous model.
The dimensions of the new QX50 are 4,693 (L) x 1,903 (W) x 1,679mm (H), and its wheelbase is 2,800mm.