fyi- if you are in a bind on a "fill up on the road", without pre-mixed, the cap of a small bottle of 2 cycle oil holds approx 4-4.5 mm.
With my ratio/tank size, 4 capfuls does a tank, 2 caps does a half. Important when traveling long distances.
When you fillup on the road, you can "get close" to standards if you know beforehand how many mm.s you need per tank, divide by 4 and add that many capfuls of oil.
Or carry a syringe, 30 cents at a veternarians office.