GTC

Ok, according to sites like http://www.designrecycleinc.com/led%20comp%20chart.html
LEDS take about 13% of the juice of incandescent bulbs. So with the '13 and '14 Stangs fully LED when parking lights switched on, having them on for hours in my sketchy neighborhood is much easier now?

WindyMustang

It should be...how long they last is a function of both the LEDs themselves and of the transformers that power them. You could grab a current meter and put it across the battery terminals to see how many amps are flowing with just the lights on, then look at the amp-hour rating of the battery to get an approximate run time if the battery is fully charged...

BeachBlv

All I know is I have left my parking lights on for long periods on accident and the car started up just fine after. Once through a whole 6 hour shift at work, once on the fourth of july for 6-7 hours. amazed me the car started but it did.