Hello, does anyone have knowledge what is the right “differential ratio” for Jaguar X100 XK8 (naturally aspirated 4.2 engine) made for United States market?

I would highly appreciate someone with expert knowledge advising me on that, hence there are multiple differential with different ratio available for Jaguar XK8 X100.

i have found that some are 3.06, but i can not believe that 3.06 will also fit XKR. Some other people say it should be 2.06, some other 3.31.

I am really confused… can someone help please?

 

the Jaguar is from 2005 year, and is 4.2 naturally aspirated (not supercharged).

 

At least early on ratio was 3.06 except for Mexico market @ 3.27. XkR and XK8 used same diff. This seems to have changed later on in production with different part numbers appearing for supercharged and non supercharged cars. 3.06 and 3.31.
If your car is N/A l would guess diff is 3.06 regardless of year.

 

My 2001 XKR has the 3.06 gear ratio