ORIGINAL: Gungadin
Yea there are differences. One difference that I have seen over the years is that some fuel producers seal each container with an air-tight seal and some don't. The ones that don't I won't purchase because a fuel container that is not sealed air-tight will absorb moisture (water) over time from the ambient environment. Containers that are sealed air-tight with a seperate seal under the cap can be stored for quite a long time with no water being absorbed from the atmosphere. It is especially a problem if you buy fuel by case lots and don't use it right away. Just my 2 cents.
This is false logic. Regardles of being heat sealed or a secondary cap on the jug is not a factor with absorbing moisture from the atmosphere. The heat seals are tamper seals only and offer no aditional protection from the atmosphere if the cap is installed correctly in the first place.
All that needs to happen is to cap the jug tightly so that when the bottle is squeezed, you can not hear air escaping the bottle with your ear held close.