u/CanadianBurger

First pic is my previous sensor. Didn’t match finger sticks at all. Second is the sensor I put on today. Within half a mmol. Anybody know a reason why the previous one could have such wild swings that were inaccurate?

Aftermarket wheels will typically have a larger bore than the hubs on our cars. While the tapered lug nuts will center the wheel, the wheel studs are not designed to handle the shearing forces encountered when hitting a bump or pothole, or even just supporting the weight of the car, especially when cornering.

That’s why you should always use hub centric rings with an inside diameter of 56.1mm and an outside dimension matching the bore of your wheels. This will put the shear stress back onto the hub where it belongs.

Hub centric rings are <$20 and can be bought on Amazon as the above example.

Edit: upon deeper research, apparently the hub rings don’t actually bear any load. But for less than $20, why not use them, if for nothing else than piece of mind during installation?