When talking ski tuning, many focus on waxing the skis as the most important thing above all else... but is it, really?
A ski that is not waxed will have an inconsistent glide, as snow conditions change from top to bottom and you hit an ice patch, or packed snow, or mush or water... so the first reason we wax the skis is to attempt to get a consistent glide from it. It is safer.
Also, a ski base that is not protected will wear faster, as the snow and ice crystals keep tearing at the fibers. A base that is full of wax is better protected and the skis retain their gliding consistency better.
A base that is full of wax also keeps the base pores closed to dirt and other particles that would like to get in there and clog it.
There are in fact rare occasions when wax significantly improves the glide of a ski base, above what a good base structure would do.
Wax is the last in the line of things that makes the skis really fast... let's take a look at the other factors...
Starting with the most important: a skier with good tactics and fundamentals/technique.
In the quest for speed, sharp edges are important, as speed is lost the more you skid your turns rather than carve them. Proper bevels are also critical, as either too sharp or too fuzzy can slow you down.
Then, a base in good condition is next - an older, worn-out base, with p-tex hairs grabbing snow crystals will be slower and quite inconsistent.
The flatness of the base is really important as well. A convex or concave base will cause all sorts of side effects.
A clean, rounded top sheet will be important to top skiers that lay the skis over so far that the top sheet is dragging on the snow...
Lastly, the base structure. You don't glide on wax (which you are supposed to brush out of the structure and also wears off at the surface quite quickly) but on the base itself and the base structure is the one that makes the difference in certain snow conditions.
Wax comes in last. In my mind, it is not definitely proven even that, all else equal, much more expensive wax makes a big difference in the results of a race. There certainly are rare conditions where some highly fluorinated wax would help (very wet snow), or molybdenum additives reduce static electricity (dry cold).
The point is that even if more expensive wax improves glide somewhat, that's not generally where a lot of the time is gained or lost in a race, except high level racing, where skills are somewhat similar and 0/100th of a second makes the difference between winning and not.
While there are races with long flat sections, where gliding does indeed make a difference, time is usually lost while turning.
Wax is however a great psychological factor. Knowing that they have a great expensive wax under their boots, boosts some racer's morale, making them faster just because!
There are those that prefer not to wax but instead refresh the base structure often - with good results or so they claim. That process however is a lot more involved and harder to do than just waxing!
You should wax every day and you should wax according to conditions, but don't skimp on sharpening the skis or keeping the base itself in good shape.
And, if you do choose to wax, make sure you follow our tuning guides.