The fuel chamber is o-ring sealed so the lighter fluid doesn't evaporate out as quickly. A Zippo will lose it's fuel by evaporation in pretty short order.
But overall I'm gonna say that my Zippo works better in cold conditions than my Exotac does, within the limited testing I've done.
You can use a bicycle inner tube that fits snug over a Zippo and it will slow the evaporation/leakage of the fluid.
