Impressive, so far.
I haven't really put this cooler to a proper test, but I did place 5 frozen ice packs in the cooler, leaving the cooler for 24 hours in my Tesla Model 3's trunk well. The car was parked in an open carport and was exposed to temperatures exceeding 90F Degrees. When I retreived the ice packs, I found them to be about 60% frozen. So, I expect that if I place pre-chilled items in the cooler with frozen ice pack, everything should remain chilled.