I was looking at the tyres on my UK pre-HE XJS recently, since I wanted to understand more about DOT codes.
I acquired the car in 2016.

The tyres on the rear are Michelin 205/70 VR15 XDX. The DOT code is FHYT A8H X 439.
The tyres on the front are Dunlop SP Sport Super D7 205/70 VR15. The DOT code is DOT DD YT RAF 434 (with a small raised triangle at the end).

The last MOT certificate I have is dated April 1988, showing a mileage of 23,245. The current mileage is 24,135 (not been out of the garage in about 30 years).

Regarding the front, I assume the tyres were made in the 43rd week of 1994 (due to the triangle). The rear tyre DOT code suggests a date of 43rd week in 1989.

If this is true, it does not correlate with the mileage or the end of the MOT certificates. The tyres do not look to have a full depth of tread on them.

So I am a bit confused. BTW, I have no intention of driving the car on these ancient tyres - there is other work to be done before it is let out of the garage.

The other confusing issue is the build plate in the engine bay. There is no plate on either left or right door strut. A photo of the build plate is shown below.
The car number plate is 'T' reg and the V5C says first registered 1st January 1979.
The VIN ends 100813. Jaguar Heritage Trust website suggests this was made in 1978/9. In those days, was it September that indicated the Manufacturer Year split? JHDT states VIN starting 101835 were from 1979 (but I don't know which month this means).

The other issue is the Paint, Trim and Build Date in the photo. Nothing is entered for Paint and Trim data - I don't know why.
The Build Date code says 'JR'. I presume this is Year and Month codes, but how do I decode it?

I'm sure someone can shed some light on the above - I would be very grateful.

Dan

 

Hi Dan,

Jaguar's year are classified as Jan to Dec.
The decoding of JR is Month/Year so J=Sept and R = 1978.

VINs only appeared in 1978 so we know it's no earlier. The 1979 VIN would have started in January. I have a March 1979 car that's numbered only a couple of hundred cars later.

I've no explanation for the missing paint and trim codes, but mine is exactly the same.

Regards
David

 

Thanks jag_sticker. It's great to know the build date. I will probably follow this up with Heritage Certificate request.
I will also rifle through all the previous owner's documents to see if any other useful info can be dug up.
Is it possible to find the code references you used used to decipher the 'JR'?
Is it on the web somewhere?

 

A = Jan
B = Feb
C = Mar
D = Apr
E = May
F = June
G = July
H = Aug
J = Sept
K = Oct
L = Nov
M = Dec

Years follow the same approach (not using I,O, Q and Z) to give R = 1978, S = 1979 etc.

 

 

Could be that the owner had more than one XJS and swapped the wheels and tyres about?