... by the chronograph function is not too drastic, maybe two to four hours, normally even less. So a fully wound 7750 should still run about 40 hours.
For longer road trips, I do use the chronograph for several hours, and there is also sense in using it permanently: if a chronograph has a 12 hours-register, you can use it as a second time zonem if you don't have any other indication for that.
Regards,
Marcus