Nissan KR engine

The Nissan KR engine family consists of three and four-cylinder all-aluminum turbocharged gasoline engines in both 12-valve and 16-valve versions with a variable compression ratio and variable valve timing developed by Nissan.

KH5T
The KH5T is a 1461 cc DIG-T (Direct Injection Gasoline-Turbocharged) inline-3 12-valve engine, with a bore x stroke of 79.7x81.1 mm.. Power output is 160 PS and 240 Nm of torque.The variation in compression ratio ranges between 8:1 and 14:1. This is achieved by the movement of an actuator which changes the length of the piston stroke according to the demand for power.

Applications:
 * 2022–present Nissan Qashqai e-Power 190 PS and 330 Nm of torque

KR15DDT
The KR15DDT VC-Turbo 3 cylinder engine is firstly introduced in the fourth-generation X-Trail. Like the name VC-Turbo suggests, this engine uses a variable compression ratio that allows for high power output and high fuel efficiency at the same time. Due to this, this engine won Nissan the 19th trophy in the Wards 10 Best Engines and Propulsion systems awards of 2022; judge Drew Winter described it as “Very smooth, exceptionally quiet during idle, pleasant to drive in traffic or on the highway”, among other comments from judges such as “This engine inspires words that never have been uttered in the same sentence as 3-cylinder engine”.

Applications:
 * 2021–present Nissan Rogue/X-Trail (T33) 204 PS, 305 Nm

KR20DDET
The KR20DDET was announced at the 2016 Paris Motor Show as the VC Turbo which had Nissan's new variable compression technology. The engine was introduced to Nissan's production cars in 2019 in the Infiniti QX50 and the Nissan Altima replacing the previous V6 options. It was touted as the world's first production-ready variable compression ratio engine.

Applications:
 * 2017–present Infiniti QX50 (J55)
 * 2021–present Infiniti QX55 (J55)
 * 2022–present Infiniti QX60 (L51)
 * 2023–present Nissan Pathfinder (R53) (China)
 * 2018–present Nissan Altima (L34)

NHTSA investigation
On December 13, 2023, American agency NHTSA opened an investigation into customer complaints of engine failure in the Nissan's KR15DDT and KR20DDET engines, the former being used since the Nissan Rogue update in 2022. The complaints allege engine failure, loss of motive power, engine knock, or noise and/or metal chunks and shavings being found in the oil pan of vehicles with these engines. The cause appears to be seizures and damages to the main bearings and L-links. Nissan stated that they are attempting to address these failures by changing their manufacturing process.