The Nissan ZD30 engine family is a 3 litre (2953 cc), inline four cylinder, diesel engine that replaced the Nissan QD engine. Available in both traditional turbo, variable geometry turbo (aka VGT or VNT), and non turbo versions. The engine uses a Drive-by-wire engine management system with a draw-through MAF sensor. Produced from 1999 - current, the newest models feature a common rail design.
The power differences stem from types of vehicles and routing of necessary pipings, as well types of manifold with different features. Engines that produce 170 hp (130 kW) have MAF sensors incorporated in them, while the 120 hp (89 kW) and 130 hp (97 kW) versions do not use a MAF sensor. Conversions can be done using the ECU from any of the higher horsepower units using the MAF sensor along with the MAF, which has to be wired into the loom of the 120 hp (89 kW) and 130 hp (97 kW) versions.