The lure of the Le Mans 24 Hours and a full programme in the World Endurance Championship with Ford was too much to persuade Andy Priaulx to remain with BMW.
The Briton, who won three World Touring Car Championship titles with BMW, opted against staying with the German manufacturer for a 14th season in favour "racing at the highest level possible" to take up the offer of a WEC seat with Ford Chip Ganassi Racing.
"It would have been more comfortable remaining with BMW and I would have had other benefits in staying, but the decision was all about the racing," Priaulx told Autosport.
"I would have raced a BMW in the GT Daytona class of the IMSA SportsCar Championship [for the Turner Motorsports team] and continued in the British Touring Car Championship [with West Surrey Racing], but that doesn't even come close to what I now have with Ford.
"It's about going to Le Mans and winning big races; having the opportunity to win the important stuff meant a lot more to me than anything else. "
Priaulx revealed that he was interested in racing for Ford the moment he heard rumours of the programme and explained that he would have been open to joining its attack on the IMSA GT Le Mans class in 2016.
"I would have been happy being part of either programme," continued the 41-year-old, who has a two-year deal with Ford.
"I have experience in the US with BMW and love the racing out there, and I knew that the American team was planning to do Le Mans.
"I've been on the podium at Le Mans with BMW [in 2011] and it was something that I really wanted to do again."
Priaulx was confirmed as one of the drivers for the two Ford GTs entered in the GT Pro class of the WEC yesterday along with Olivier Pla, Stefan Mucke and Marino Franchitti.
The pairings in the two entries and the additional drivers for Le Mans will be decided at a later date.
Priaulx will make his debut with Ganassi in this month's Daytona 24 Hours in one of a pair of two Riley-Ford EcoBoost Daytona Prototypes the team is fielding in the IMSA opener on a one-off basis.