Help with VIN decoding

[foibles]

Hi everyone - I am hoping someone can clear this up for me.

OK...so VIN decoders largely tell me everything I need but;

..in comparing two Porsche 928's, I have noticed that one reads

WP0ZZZ92ZHS8413xx - it is an 87 model, whilst the other reads
WP0ZZZ92ZJS8405xx - it is an 88 model

You'll note that the only differences are position 10 - wherein H means 87, and J means 88, as well as positions 13 and 14.

But this what I am perplexed by......the 87 (VIN position 10) has a serial number that is greater than (at positions 13 and 14) the 88 model.

I would have thought this makes no sense, because serial numbers are not an 'annualised' number, but relate back to the actual model of the vehicle. Therein, an 87 model car should have an earlier serial model, than the 88 model car.

Can someone help edify me as to what I am missing here. How can it be that an earlier dated car of the same version (both are 928 S4) has a LATER serial number, unless of course the serial number is 'annualised' (which I would not have thought to be the case)?

Thanks,

Foibles

[stratfordshark]

The 84 is not beginning of serial number. The serial is the final 4 digits and is tied to model year for a 928 of that era. All 928s had an 8 in position after year to mean model 928. The next digit 4 refers to body type/engine type

[foibles]

Thank you - am a bit the wiser now. Cheers!

[stratfordshark]

Glad to help. I should have added that the serial number is annualised as you suspected may be the case. 4 digits was always enough to record annual number (around 61000 cars manufactured over the 77-95 life)