Are you following the 9-5 4-cyl drama (at least here in North America)?
All the 9-5 models are turbocharged, 4 or 6. Saab recommended a 10 000
mile (16 000 km?) oil change interval. As well, they installed smaller
low-friction piston rings, a lower-friction oil pump, an OBD-II
compliant PCV system and several other enhancements that really give a
much better fuel efficiency on these new motors, designated B205 (2,0
litre not in North America) and the B235 (standard 9-5 USA market
motor). However, this puts a lot more stress on the engine oil than you
had with the older B204 and B234 engines. Of course, since Saab said
change oil at 10k miles, people are putting in the 69 cent at Wal Mart
a quart oil and changing it at 12k or more miles and putting a crappy
Fram or something oil filter that clogs and goes into bypass at 6 k
miles.

Result - engine starts to sludge up. The timing chains start to make a
little rattling and in no time the engine is junk. This is a far cry
from the old B202 engines that basically could use molybdenum grease
for oil and run a billion miles and still look like new on the inside.

If the engine is properly maintained the B2x5 engines can run a very
long time as well and serve the owner with excellent economy and
performance, especially in R tune. However unless you have a proper
maintenance log for it (and then Saab's 8-year warranty will apply too)
it might be better to not touch it. Mind you, 9-5 Aero cars
(particularly manual transaxle) probably had "more enthusiast" owners
who took much better care of them...