I don't know if the Alpina is "slower". It doesn't have the same engine as the regular Z8. The regular Z8 has a S62 5.0, same as the M5. The Alpina has a 4.8 liter, which from what I understand is a punched out 4.6is motor from the X5. The Alpina has more torque, but fewer HP, but seeing how it's a damn automatic, it probably is a bit slower.