Hi Garry:
         I have tried both OEM and after market local "Cdn. Tire"
varieties and the results are about the same.
With any luck they will last two ot three years. Once in a while you
will get a 'dud' that fails in a year.
As you said, they are weaker in cold weather but they seem to recover
in the warmer season.
        As far as .." Care of future units?" is concerned, However
improbable and impractical it is, I would think keeping the door open
(cylinders extended) is probably better than left closed. It's
probably better to remove them altogether for storage in the winter
months. Having said that, I'm not sure I would go to the trouble of
doing that, let alone even remember to do it. But it might double the
life of the cyclinders. I.M.H.O.

Summary: Keep an eye peeled for sales at your local auto supply shop
and keep one on hand as a spare.

                                David (dsl82westy)

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>Anyone have suggestion on gas tubes that should hold rear door up.
>
>They don't seem to survive cold winters.
>
>Are there preferred quality/types/brands recommended for replacement?
>
>Care of future units?
>
>Garry