the main difference during the 993 production run was the varioram intake system introduced on the '96s. ( a little more HP and a fatter torque curve)
the '95s had an engine wiring harness problem that is now a recall and a free fix.
the valve guide wear problem is hit or miss. a lot of people are approaching 100k miles without a problem, others have had to do their heads at 50k miles.
blocked secondary air injection ports can affect all model years, but can cause more grief (aka CEL) with the '96 and up OBD II cars. If the ports aren't completely blocked, there are now DIY write-ups on flushing the system out to clean up the carbon build-up to hopefully fend off the dreaded CEL. If the car suffers from high oil consumption due to excessive valve guide wear, and that is the source of the carbon build up- obviously a valve job is the only real cure
'95 cars are easier and cheaper to chip, '96 the hardest and most expensive.
The AWD system seems to be fairly trouble free. But, it is obviously something else that can go wrong on the car, and i don't think any of the components are cheap. where you live and the road conditions you drive in will help you make the 2wd vs. 4wd choice.
The TTs
AFAIK are the same for '96 and '97, other than the aforementioned chip diffrence. I think the only Turbos made in '98 were the $$ Turbo S models.
Basically, there isn't a really good reason to choose one particular model year over another; spend your time being choosey when it comes to the condition and maintenance record of the cars you're looking at. And the usual advise- Get a PPI !
The first US 993s are now ten years old!
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