I have similar condition in Milwaukee, WI. I have been using Mobile 1 syth 10w30 for ages in my NG900 SE 4cyl-Turbo... however now it's dedicated for winter use only and the M3 has taken over Spring/Summer/Fall use.For 5k mi OCI you could really use just about any full syn. Keep in mind that Saab recommends an ACEA A3/B3 rated oil for better durability & protection.
Personally, I favor Mobil products simply because I believe (from several years of research) that they put the most R&D into their products to get the best product on the market. But that's just my bias & others favor other products for their own reasons.
I'd specifically recommend one of these for our Swedish turbos:
10W-40 High Mileage
10W-30 High Mileage
All of these meet ACEA A3/B3, so they provide a stronger film of oil & have better additive packages. (5W-40 actually meets ACEA E7, so it has an even more fortified additive package than A3/B3/B4.)
Rotella T6 5W-40
There are other good oils out there, too.
My first choice would be 0W-40 as a year-round oil in a northern climate. Here in Northern CO we have summer highs around 100F & winter lows around 0F. When we had our '99 9-3 T5, 10k mi OCIs weren't a problem (especially once I added mid-OCI filter changes). Now that we have an '02 9-3 T7, I've been sticking with 5k mi OCIs due to the greater stress the T7 system places on the oil. Of course, I have Oil Compulsive Disorder :cheesy:, so I've been using M1 5W-40 in my 9-3 & 0W-40 in my n/a C900. As long as you keep it topped up to the 'Full' mark on the dipstick you should be fine with any of these oils in your climate.
Suggestions for a cold weather oil? 5W40?