Joe M is right as he usualy is , but it depends on the area, location,
sun exposure etc and the Garage, mine had no vents and held moisture,
now I put them in and it is great.

Overall a dry garage reduces rubber rot, sun exposure and moisture
damage- we must include good garages, built for cars in this equasion ,
many are crap-many are good. A car in a good garage will last longer,
in a crap garage less. Few are equal