Jaguar XJR and XJ8 are two common trims of the XJ series. There are certain differences between the two, especially when you check some features that are present in the two. XJR comes with more additional features compared to XJ8. As a result of this, XJR tends to be more expensive compared to XJ8. The absence of a supercharger in XJ8 is a differentiating feature between the two.
This means XJR comes with a supercharged engine. The engine in XJR helps to draw a larger volume of air into a section of the engine known as the combustion chamber so that the fuel being supplied can burn completely. The implication is that it will allow the in XJR to produce power more efficiently compared to the one in XJ8.
Another difference between XJR and XJ8 is that the former looks more luxurious compared to the latter. All these advantages which XJR has over XJ8 are the reason why most people go for it except for those who can't afford it.