AJ16
Both the 3.2 and 4.0 were substantially revised for the 1995 launch of the new X300 saloon. These are the "AJ16" engines, both now featuring coil-on-plug distributorless ignition, new engine management systems, magnesium alloy valve covers, revised pistons and other detail changes. The AJ16 was discontinued with the launch of the AJ-V8 (XK8 and XJ8 in 1996/7).
Read more about this topic: Jaguar AJ6 Engine