Vic Smith wrote, on Mon, 14 Dec 2015 08:08:30 -0600:

They are basically marks on tires which are supposed to indicate
"balance points." A red dot represents radial runout, a yellow dot
represents the "light" spot of the tire.

Everything Vic Smith said is right on the money.

I'm still confused about one thing though, which is that I've read
*everything* on the net about these dots (those who know me can
believe that, by now), and I remember seeing slightly different
answers depending on which manufacturer makes the tires.

So, while Vic Smith is 100% correct, I'd always doublecheck with
the actual manufacturer of the tire that I'm mounting (and, for the
tires I most recently mounted myself, Vic's answer is spot on).

The purpose is to reduce the imbalance from the very beginning.

But if you balance tires with a Hunter Road Force balancer, which is
how I get my tires balanced, the dots end up at random locations.

I'm sure Vic Smith knows what he's talking about, but, upon first
inspection, I don't understand this statement because the tires go
on the rims by the dots *before* the tires get balanced on the machine.

I guess what Vic Smith is saying is that a "proper" tire mounting
job would be to mount the tire according to the match mounting
marks on the rim and the dots on the tire, and *then* spin balance
and *then* deflate the tire and slide the tire to get the best
balance *before* adding a single ounce of weight.

Of course, this is a *perfect* procedure, but, I have *never* seen
anyone do it on "my" tires when mine are dynamically balanced.

The tire monkey knows *how*; it's just work and, most customers
don't know the difference.

If I was bubble-balancing my own tires, I'd use them.

Yup. I have only mounted and balanced 6 tires (5 of my own and one
for a friend on a SUV). Mine are stock BMW alloy wheels, which have
match-mounting marks and which were pretty well balanced when I
match mounted the tires according to the dots. The static balance
was pretty good with very little zinc weight being added.

The SUV steel rim was harder. First, I couldn't *find* the match
mounting mark, and it took more weight (a lot more) than the BBS
alloy wheels did.

The neighbor didn't complain about vibration, even though I warned
her that she may feel vibration (it was a front tire besides).

My kid worked mounting tires at Just Tires for a couple years and when
I mentioned the dots to him he responded with, "Oh yeah, I noticed the
dots sometimes. Didn't know what they were for. Interesting"
And some tire manufacturers don't mark their tires with balance
points.

Heh heh. This is why I call them tire monkeys (pardon my slur).
I buy from TireRack and I have them shipped to my address so I can
bring them to any tire-rack-recommended dealer.

First I brought them to Goodyear, and when I told them to match
mount, they asked "me" where to put the dots! True story!

I had to look it up because, as I said, it can change based on
what the manufacturer says.

The next time I replaced tires, for my wife's car, I went to a
different shop where I brought the printout for match mounting
with me. Again, they had to read the damn thing.

Most tire monkeys were *taught* this stuff, I'm sure (because it's
basic tires101; but they don't give a hoot, and most of their
customers don't know any better.

As always, if you want the job done right, you have to do it yourself.