Nissan VR30DDTT

Infiniti's 3.0-litre twin-turbocharged V6, replacing the naturally aspirated VQ in the Q50 and Q60 — a modern direct-injected engine with an electric wastegate, a water-to-air intercooler and turbine speed sensors, which is unusual and gives the control system far more authority over boost than a conventional arrangement.

That sophistication is where its complaints come from. The water-to-air charge cooling circuit has its own pump and radiator, and a fault there produces heat-related power limiting that reads as a boost or knock problem rather than as a cooling one — a distinction worth making before any turbocharger is suspected.

The engine is recent enough that long-term patterns are still forming, which is worth saying rather than filling in. What is established is that it is sensitive to oil condition and heat, in the way any small-displacement twin-turbo V6 making this specific output must be.