1992 BMW 325i sedan

hey i was wondering if anyone knew how fast a 1992 BMW 325i sedan accelerates. In the manuel it tells you 0-50 in 5.6 seconds but now more cars are from 0-60 so i was just wondering if anyone knows how fast the car accelerates from 0 to 60. Also i have a question about the stock amplifier. I took it to good guys and they said that it was only 2 ohms but i think it is actually 4. are they just trying to get me to buy a new amp or is it actually a 2? Thanks