I don’t really see a huge difference either, but you can look up the design specifications. Here is a quote from another user that has already done so.
The technology is already spec’d to be less accurate at higher BG’s than lower. This is because the useful span of accuracy for the enzymes used on the sensor is quite a bit narrower (about 100 mg/dl) than we deal with (under normal circumstances), 200 or so. The system was deliberately designed to nail that delta to the hypo end of things, rather than the hyper end. So, it’s most accurate in the low range – 40-100 – than up high. When BG starts to get about 170 or thereabouts, the inaccuracy increases.One of the upshots of this is it’s better to calibrate lower than higher. If you calibrate high, it’ll can make things less accurate down in the hypo range.If you’re getting reasonable accurate down low (+/- 10), then don’t sweat the high end, which can easily and routinely be off by as much as 40 or 50.
