Usually happens after longer period of driving and when outside temperatures are warmer ( 90 degrees or above). The engine stalls and will always restart within minutes sometimes just seconds. Although temperature gauge doesn't rise, I seem to get further before recurrence when I turn off AC and run heater to dissipate heat. Will occur more often pulling up a steeper grade also.

Engine cuts off at hwy speed. After coasting to a stop and turning off the ignition sometimes it starts on the first try and sometimes it takes a few cranks. I've noticed it happens when the ambient temperature is above 70 degrees and driving long distances.