Jaguar AJ-V6 engine

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Jaguar AJ-V6
Manufacturer Jaguar Cars
Production 2000–
Combustion chamber
Configuration DOHC 60° V6
Predecessor Jaguar AJ16

The Jaguar AJ-V6 engine is a specialized version of Ford's Duratec 25/30 V6. One notable addition is the use of variable valve timing, a feature also shared with Mazda's version of the engine. It is available in 2.1 L, 2.5 L and 3.0 L displacements.

Jaguar's AJ-V6 engine has an aluminium engine block and aluminium DOHC cylinder heads. It uses SFI fuel injection, has 4 valves per cylinder with VVT, features fracture-split forged powder metal connecting rods and a one-piece cast camshaft and has direct-acting mechanical bucket (DAMB) tappets, these design aspects differentiating the AJ-V6 from the Ford and Mazda versions.


The AJ20 2.1 L (2099 cc) version has an 81.6 mm (3.2 in) bore and 66.8 mm (2.6 in) stroke. Although it displaces nearly 2.1 litres, it is marketed as a "2.0". It produces 157 hp (117 kW; 159 PS) and 148 lb·ft (201 N·m). The compression ratio is 10.75:1.

This engine is used in the following vehicles:


The AJ25 is a 2.5 L (2495 cc/152 in³) version built in Ford's Cleveland, OH #2 factory. It is stroked to 79.5 mm (3.1 in). It delivers 192 hp (143 kW; 195 PS) at 6800 rpm with 178 lb·ft (241 N·m) of torque at 3000 rpm from 10.3:1 compression.

This engine is used in the following vehicles:

  • –present Jaguar X-Type 2.5, 194 hp (145 kW; 197 PS) and 180 lb·ft (240 N·m)
  • –present Jaguar S-Type 2.5 (UK), 201 hp (150 kW; 204 PS) and 185 lb·ft (251 N·m)


The AJ30 is a 3.0 L (2967 cc) version and is the most common, especially considering the Duratec 30. It has an 89 mm (3.5 in) bore and shares the 2.5's 79.5 mm (3.1 in) stroke. In the X-Type, it produces 231 hp (172 kW; 234 PS) and 209 lb·ft (283 N·m).

This engine is used in the following vehicles:

  • 2000–2009 Jaguar S-Type, 240 hp (179 kW; 243 PS) and 216 lb·ft (293 N·m)
  • 2002–2009 Jaguar X-Type, 231 hp (172 kW; 234 PS) and 209 lb·ft (283 N·m)
  • 2009–present Jaguar XF, 240 hp (179 kW; 243 PS) and 221 lb·ft (300 N·m)

The Jaguar XF will debut a refined version of the AJ30 with continuously variable cam-phasing and variable geometry air intakes to increase power and broaden the powerband up to its 6800 rpm redline.


The AJ126 is a 3.0 L (2995 cc) 90° petrol V6, having a bore of 84.5 mm (3.3 in) and stroke of 89 mm (3.5 in) with a 10.5:1 compression ratio. It is liquid cooled featuring direct fuel injection, four overhead camshafts and four valves per cylinder. There are two versions differing in power produced, a standard version making 340 hp (254 kW; 345 PS) at 6500 RPM and 332 lb·ft (450 N·m) between 3500-5000 RPM and a high-performance variant making 380 hp (283 kW; 385 PS) at 6500 RPM and 339 lb·ft (460 N·m) between 3500-5000 RPM.

The main structural components of the engine are all manufactured from aluminum alloy. The engine is built around a very stiff, lightweight, enclosed V, deep skirt cylinder block. A structural windage tray is bolted to the bottom of the cylinder block to further improve the block stiffness, minimize NVH (noise, vibration and harshness) and help reduce oil foaming. To further enhance the stiffness of the lower engine structure, a heavily ribbed sump body is installed. The sump body also helps to reduce engine noise.

The engine uses a Bosch high pressure direct injection fuel system with fuel pressure provided by two, cam driven high pressure pumps which are driven by a dedicated camshaft. The high pressure pumps supply the fuel rails which in turn supply the three injectors for that bank with fuel at a controlled pressure.

The four camshafts incorporate VCT (variable camshaft timing). VCT allows the timing of the intake and exhaust valves to be adjusted independently of each other. The VCT system is controlled by the Bosch ECM (engine control module) using information from CMP (camshaft position) sensors.

The supercharger is located in the 'vee' of the engine and is driven from the crankshaft by a dedicated secondary drive belt.

The engine meets EU5 emission regulations in Europe and Rest of World (ROW) and ULEV 70 emission regulations in North American Specification (NAS) markets.

The direct fuel injection system, advanced piston and combustion chamber design and the supercharger provide improved fuel consumption and emissions.

The AJ126 V6 is basically an AJ133 V8 engine that has 2 less cylinders and is made on the same production line as the AJ133. It shares a very similar block as the supercharged V8 AJ133, with some differences such as reduced bore size. Cylinder heads are also derived from the V8 engine. The engine features a balance shaft to drive the oil pump and balance the crankshaft.

See also[edit]