RR 3.0 Ingenium I6 Diesel D300 to D350 Factory Upgrade

Jaguar Land Rover released the 3.0-litre straight-six Ingenium diesel engine in multiple states of tune—D250, D300, and D350—from a single unified hardware architecture[reference:0]. The D300 and D350 variants share identical mechanical components: the same twin-turbocharging system, the same fuel injection hardware, the same 48V MHEV assembly, and the same ZF 8HP automatic transmission[reference:1]. The performance gap between these two factory variants exists entirely within the Powertrain Control Module (PCM) calibration. This product page explains how the D350 factory calibration upgrade works, what it changes, and why it preserves the engineering integrity JLR designed into the AJ20D6 engine family.

One Engine, Two Factory Calibrations

JLR engineers calibrate the PCM to deliver different power and torque ceilings for each trim level. The D300 calibration caps boost pressure and fuel delivery to produce 300PS (221kW) and 650Nm of torque between 1,500 and 2,500 rpm[reference:2]. The D350 calibration raises those same parameters to 350PS (258kW) and 700Nm between 1,500 and 3,000 rpm[reference:3]. The engine, turbochargers, injectors, cooling circuit, and exhaust aftertreatment system remain identical across both variants[reference:4]. No mechanical component changes when you move from D300 to D350 specification.

What the D350 Calibration Delivers

The D350 factory software unlocks the full performance envelope of the Ingenium I6 diesel platform. Power rises by 50PS and torque rises by 50Nm, producing a measurable improvement in real-world drivability. The 0–100 km/h sprint shortens from 7.4 seconds in the D300 to 7.1 seconds in the D350[reference:5]. More importantly for towing and loaded driving, the D350 calibration extends peak torque availability to 3,000 rpm, giving the engine a broader and more responsive power band. Mid-range acceleration improves for overtaking and highway merging, and the integrated 48V MHEV system synchronises with the upgraded parameters to maintain smooth torque delivery[reference:6].

Genuine JLR Calibration, Not an Aftermarket Remap

This upgrade uses the factory D350 calibration data that JLR preloads within the vehicle’s firmware. The process flashes the official PCM calibration and updates the Car Configuration File (CCF) to activate the D350 powertrain flags, exactly as the production line would configure a factory D350 vehicle[reference:7][reference:8]. The upgrade retains full dealer diagnostic access, over-the-air (SOTA) update compatibility, and factory emission compliance[reference:9]. All safety limits, thermal protection protocols, and DPF regeneration logic remain untouched. The calibration is also fully reversible: the original D300 software can be restored at any time because the process changes only software within the engine control module[reference:10].

Engineered for the AJ20D6 Architecture

The Ingenium I6 diesel—designated AJ20D6—uses a 2,997cc displacement, an 83.0mm bore, and a 92.3mm stroke, with four valves per cylinder and variable valve timing[reference:11]. The boosting system pairs two close-coupled, series-sequentially arranged turbochargers with Twin Electric Variable Nozzle Technology, delivering 90% of peak torque in just over a second at 2,000 rpm[reference:12]. The all-aluminium construction saves 80kg over the previous V8 diesel, and the engine meets RDE2 and Euro 6d-final emissions standards with 48V MHEV technology[reference:13][reference:14]. The D350 calibration operates entirely within the engineering limits JLR validated for this hardware.

Specifications

Compatibility and Process

This upgrade applies to 2020MY-onward JLR vehicles fitted with the 3.0-litre Ingenium I6 diesel, including Range Rover and Range Rover Sport models[reference:15]. The procedure uses the vehicle’s ENET diagnostic port and the JLR Engineering Tool with a JLR Enet WiFi adapter for DoIP programming[reference:16]. You supply the VIN for compatibility verification, and the calibration flashes remotely over a secure connection. The entire process preserves the original CCF backup for reversibility and leaves no aftermarket modifications in the vehicle’s software architecture. The result is a genuine factory D350 specification, activated through the same calibration pathways JLR uses on the production line.