I live in Michigan and I’ve seen negative temps in winter. After several conversations w/ some shops and a couple tuners, I went w/ the IAG Competition series AOS. I haven’t had any issues yet, however short drives in super cold temps...like a few miles or only a few minutes...will sometimes yield some leakage out of the breather line under the car. It’s quite minimal and only happens in those circumstances. I’ve had it on a little over 2 years now.