Haven't actually time tested this yet. Using an AW14500 (NOT IMR!) the output is really great to put it mildly. Heat is no issue at all initially. After a minute or two on high there isn't any significant heat. By four minutes, it's hot and beginning to become uncomfortable but simply dial down the output with the QTC and the temp begins to drop. This light uses Peak's Direct Thermal Transfer to draw the heat away from the XML, to the heatsink and thermal epoxy, and out to the body. In short, the heat is easily managed. Not so with an IMR battery which allows current far in excess of what the light can handle. Tested a pre-production sample with an IMR and WOW!!! - for 20 or 30 seconds before it became too hot to handle. The beamshots don't do justice to the actual output of this light. Down a dark street with no streetlights or moon, the little wonder was stunning in comparison to the headlights of the Chevy. My camera and skills, unfortunately, weren't able to capture any representation of the comparison. In short, the El Cap Ultra X won't throw like the Chevy headlights, but it will light up nearby areas far better than the truck.