The Mexico 66 is roughly true to size in length for a foot of average width. Take your usual size. The reason you will find people online insisting it runs small, and other people insisting it runs large, is that they are both describing the same thing badly: the shoe is narrow, and a narrow shoe feels short.
Why the advice online contradicts itself
Onitsuka Tiger is generally reported to run narrower than Nike or Adidas, and the Mexico 66 has one of the slimmer toe boxes in the range. It is a low-profile, flat-soled shoe descended from a 1966 running silhouette, and it was never cut generously.
So a person with a narrow foot tries their usual size, finds the length fine, and reports true to size. A person with a wide foot tries the same size, feels pressure across the forefoot, interprets it as the shoe being too small, sizes up half, and reports that it runs small. Both then post their conclusion as though it were a property of the shoe.
It is a property of the foot.
What to actually order
| Your foot | What to order |
|---|---|
| Average or narrow width | Your usual size |
| Wide, or high volume across the instep | Half a size up |
| Between sizes | Half a size up |
| Coming from Air Force 1 | Often half a size up from your AF1 size, since the AF1 runs large |
These are widely reported tendencies rather than manufacturer specifications, and they will not survive contact with an unusual foot. We would rather tell you that than pretend a table settles it.
The break-in is real, but limited
The upper is thin leather and it does relax across the width over the first couple of weeks. That is genuine, and it means a fit that is snug rather than painful on day one will usually come good.
What does not happen is length. The shoe will not get longer. If your toes are against the end in the shop, they will be against the end in a month. Do not buy short and hope.
If the width is the problem
If you try the Mexico 66 and the issue is genuinely across the forefoot rather than at the toe, sizing up is an imperfect fix, because you gain length faster than you gain width and end up with a shoe that slips at the heel. Two alternatives in a similar register:
- The Adidas Samba OG is also narrow, so it solves nothing. Avoid if width is your issue.
- The New Balance 530 is the more accommodating low-profile option and generally reported as roomier.
- The Asics Gel 1130 sits in similar territory with more volume through the midfoot.
Frequently asked questions
Do Onitsuka Tiger Mexico 66 run small?
Not really in length. They run narrow. For an average-width foot the length is roughly true to size, but the slim toe box makes the shoe feel smaller than it measures, which is why so much online advice says to size up.
Should I size up in Mexico 66?
Only if you have a wide foot, a high instep, or sit between sizes. Otherwise take your usual size.
How do Mexico 66 compare to Nike sizing?
Onitsuka Tiger is generally reported to run narrower than Nike. If you are coming from the Air Force 1 specifically, note that the AF1 runs large, so many people take half a size up when moving across.
Do Mexico 66 stretch?
The leather upper relaxes across the width over the first few weeks. The shoe does not gain length. A snug fit will ease. A short fit will not.
Are Mexico 66 good for wide feet?
They are one of the less suitable options. The toe box is slim by design. If you have a genuinely wide foot, a roomier silhouette will serve you better than sizing up in this one.