Interestingly enough, the better the cooler, the better off you are pre-cooling it. Most of the better coolers are made of denser material and therefore have greater mass. The insulation itself has the ability to not only insulate, but to absorb heat or cold and hold it, more so than a low cost cooler. In our experience, you will get better results with a low end cooler in the first 6 hours then with a high end cooler if both coolers start out warm. When you pre-cool a cooler, you bring it’s temperature closer to the intended food temperature goal, thereby not wasting energy cooling the cooler. When the better cools are pre-cooled, they will substantially outperform a pre-cooled low end cooler.
How do you pre-cool your cooler? Many people use sacrificial ice to do this. A better way is take an extra Cooler Shock ice pack out of the freezer and put it in your cooler 4-8 hours before use. When it’s time to use it, put that ice pack back in the freezer and break out your fresh ones for your trip.