The 3 L engine in the Jaguar XJ is at the top end of what this displacement produces — serious injection pressure, sophisticated turbocharger management, and a factory calibration that leaves room on the table by design. These engines are well-engineered enough that a careful, dyno-developed map extracts meaningful gains without asking anything the hardware isn't already built to handle.
Our dyno-developed map for the Jaguar XJ adds an average of 29 kW (21%) at the wheels and 133 Nm (19%) of engine torque. That's the target band we work towards on this engine — meaningful gains you feel every time you pull out to overtake or climb a grade, without pushing the injectors, turbo or transmission anywhere near their limits.
In practical terms, that works out to around 7 fewer tanks of diesel over 40,000 km. At a typical 15,000 km annual mileage, most Jaguar XJ owners save roughly 171 L and $205 per year at the pump — purely from improved combustion efficiency at part-throttle, where diesels spend most of their time.
This Jaguar XJ variant ran from 2016–2018. The factory calibration changed very little across that production window; we have the original file for each year and always confirm which one matches the car in front of us before we start.