Maybe the admins will make this a sticky at the top of this, the xj40 and the xj300.

This is quit simple, but it confused me when i started going on different jaguar forums.

A XJ6 was made by jag for almost 40 years. If you own a car from 1990-1994 that says xj6 on the back, you are driving an XJ40 (this applies to me)
If you are driving an xj6 newer than 1994, you have an xj300.
Anything older than 1990 is an actual xj6, and should be posting on this forum.

correction: The XJ-6 was the official factory model name for those 6-cylinder Series 3 Sedans exported to the North and South American markets until 1987. After 1987, the North and South American Sedans are officially the XJ-40, (un-officially the Series 4 XJ-6 and XJ-12), then the X-300, (un-officially the Series 5 XJ-6 & 12), then the X-308. (un-oficially the Series 6 XJ-6 & 12). The exception here is that Jaguar kept producing the Series 3 XJ Sedan (or Saloon as they are called) until 1992 for certain other markets, like Europe, Canada and Australia, but only in 12-cylinder version.

confusing? And that does not include the VanDen Plas and the Sovereign models!!

but for the purpose of this and most forums, it;s divided into the three catagories I stated.