His two younger brothers, Mikael Max and Magnus Karlsson are both motorcycle speedway riders. All three brothers represented Sweden in the 2007 Speedway World Cup, with Magnus riding at reserve. Due to the average points limit, PK had to move on in 2010 and joined Belle Vue Aces on loan.
1993 - Pocking, Rottalstadion - 8th - 8pts.
World Under-21 Finalist (1989, 1990) Swedish Champion (1989, 1991) World Finalist (1993) Speedway Grand Prix Rider (1995, 1996, 1997, 1999, 2000, 2001) Swedish General Practice Wildcard (1998, 2002, 2003) Polish General Practice Wildcard (2003) Speedway World Team Cup Champion (2000) Speedway World Cup Champion (2003, 2004) Slovenian General Practice Wildcard (2003) Czechoslovakian General Practice Wildcard (2003) European General Practice Wildcard (2003) Norwegian General Practice Wildcard (2003) Scandinavian General Practice Wildcard (2004, 2007) German General Practice Wildcard (2007) Swedish Finalist (2008).
