Real Simple it saves racers Money.
What saves racers money?
A spec tire brand rule?
Couldn't disagree more!
If your intent is to honestly save racers money, then institute a "one set of right sides per night" rule. Regardless of brand, that would save racers money per night. The problem is, it doesn't help the tire companies sell tires. Tire companies are in business to make money -- and there's absolutely nothing wrong with that! I just hate to hear the excuse of instituting a tire rule as "it saves racers money." It most certainly does not. If I have enough money for one set of tires (and they don't happen to be the brand you enforce), then I cannot run at your track without buying your brand of tires = that COSTS me MORE money, or that rule just excluded me. If I get free, or discount tires, from a sponsor (that isn't the brand that you enforce), that costs me more money or excludes me. If I run used tires (again, they're not the brand you enforce), that excludes me. If I choose to run a cheaper tire (pick one - Unilli, Kings, just about any, etc.) then you have excluded me with your "money saving tire rule."
I've run both open tire tracks and spec tire tracks and I can show you the bills from running both - from karts over 40 years to sprint cars 15 years. Spec tire rules are the same - they benefit the two parties that signed the contract the most: the tire company and the promoter. To be competitive at a Burris only series, you're still going to want as many tires as you can afford and then some. I personally own more Burris tires than all other brands combined! Remember, you can only run 4 tires on the kart!
Picking the "right" 4 tires is just as complicated (or simple) with one brand as it is several brands. With one brand, you find yourself with several sets cut at different thicknesses. You have different template cuts (round cut, flat cut, etc.) Then you have several of those sets prepped differently (internal, # of ounces, outside coats, etc.)
A set of "competitive" Burris tires MUST be cut and prepped. That is not always the case with some other brands. Can you win on a set of sticker Burris? Not likely. So now, you take arguably one of the most expensive brands of tires and just made them considerably more expensive by paying a tire guy to cut, finish, etc your tires just to be on that proverbial level playing field.
Each team has one brand of tires - Maxxis, Firestone, Vega, Burris, and Unilli. On ANY given night, ANY of those tires could be fast...now each team has to buy the other 4 brands of tires (and probably a few sets of each) to have what they need in their arsenal to go compete.
Why in the world would the "have to buy the other 4 brands of tires?" I hear this argument regularly from the "pro tire rule" crowd. This is simply not true. You and I both know that you can pick one of 2 (maybe 3 brands at most) of tires and be fast ANYWHERE. Some tracks are going to be more low/no bite where your Burris, Vega, and Hoosier tires will be fast. As a track bites up, Maxxis will get fast, and if it really bites up, Firestones will be fast. RARELY (if at all) will you be at a high bite track where a Burris, Vega, or Hoosier will be fast. Same can be said about running Maxxis or Firestone at a low bite track. So, basically, you are limited to 1 or 2 brands to begin with (especially at the local Saturday night track where the track and the kart count is much more predictable. What I find more the norm is that when a midwest/northeast local track goes from a Burris rule to open tire rule, is that Burris tires are still the tire of choice there. Keeping it open tire rule allows more guys to run whatever they choose, thus not excluding anyone based on tire brand choice. I would never take a set of Burris down south to most tracks and even expect to be on pace - nor would you. Likewise, there are tracks up here that Maxxis & Firestone don't stand a chance on a typical Saturday night surface.
No one seems to want to start a spec "engine builder" or spec "chassis" rule. If you race at track "X", you need to ride on a Phantom chassis with Miller power. Now, no one would honestly think this is best for the sport (even if the sponsoring companies kicked in way more than any tire company ever would,) and the choice was the "majority." It simply wouldn't be accepted. Yet, racers typically take a tire rule on the chin being told that it is for their own good.
What I find interesting in all the great tire debates is that so many people believe that running a spec brand tire saves the racers money and evens the playing field, while we all still see the best racers with the best resources winning regardless of what brand of tire they are on. If a guy is good on open tires, he'll be good on spec tires. Take a peek inside the trailers of the consistent front runners. They have a trailer full of tires -- one brand or open. That's not because they just like to spend money -- it's because it gives them an advantage! I'll take 20 sets of spec tires over 2 sets anytime. Didn't seem to save those racers any money either.
Again, this debate gets old -- everyone is entitled to their opinions. You've got yours, I've got mine. I'll continue to sell tires of every brand and cut and prep some brands more than others. As a racer (and an American), I like the freedom to choose what brands I purchase for my own use. Most don't want the track telling them they can't drink their favorite cold beverage at the end of the night because it's not the track's "spec" brand. Even if it tastes better.