I'm curious when/how "changes" happen.

 

Are these changes like this: 12/31 something is XYZ and then on 01/01 it is ABC? That's how it seems like it's assumed (except when there's a known specific date like 1987.5 XT Turbo's).

 

A specific example: are all EJ22's Phase I up until 12/31/97....and then on 01/01/98 (for MY99) they're all the Phase II style?

 

Just wondering if there's ever overlap or how it works.

 

Subaru seems to use the VIN number to determine specifics sometimes rather than manufacture date?

I'm curious when/how "changes" happen.

 

Are these changes like this: 12/31 something is XYZ and then on 01/01 it is ABC? That's how it seems like it's assumed (except when there's a known specific date like 1987.5 XT Turbo's).

 

A specific example: are all EJ22's Phase I up until 12/31/97....and then on 01/01/98 (for MY99) they're all the Phase II style?

 

Just wondering if there's ever overlap or how it works.

 

Subaru seems to use the VIN number to determine specifics sometimes rather than manufacture date?

 

from my personal observations, the production year for the new model year started ''around'' june of the calendar year. this obviously is very loosey goosey with lots of room for error. but generally speaking it is close.

 

some websites use production dates only, like http://opposedforces.com/parts. others use model year, like http://www.car-part.com, unless they list a production date.

 

but the vin seems to be the definitive, assuming you have the data base to search , like a subaru dealer has. the vin needs to be absolute. my guess is that there is a talley sheet that follows each car through the production line which includes all of the part numbers installed on that car. or at least the numbers for the ''components'' installed on that car.

 

so if there was a 98 auto trans left over and installed in a 99 MY car, it would be documented on the talley sheet and it would fudge the change date.

 

perfectly clear , right ????