By car? 30 minute drive because of the congestion. Then I either hunt 15 - 30 minutes for parking lot or pay 170 eur/month in a close by cellar of a mall. For comparison monthly ticker for the public transport is only 30 eur.
I, too, have one – with a car I drive about 15 minutes along the innermost “ring” road whereas any combination of public transport would require at least an hour for the worst case scenario. Yes, the trip takes longer in peak traffic; luckily I can avoid those times most of the time – and it's in any case way faster than with public transport.
It was comparatively worse when I had a much shorter commute to school years ago. The 3.5 km trip would consist of more than a kilometre of walking and would at worst take way more than half an hour with buses (including the switch, without one you'd have to walk more than half the distance). Needless to say, I did not prepare for the bad days, and was late quite often.
With a car, it was literally a five minute ride.
In Helsinki, especially before 550, certain trips are lot faster with car. Currenly my school comute is 25min by car and 1h by bus. The fucked up thing is that bus routes are so winding that they compete with bicycle in speed and reach.