You won't find Super UDT, it obsolete.
There is UDT, and Super UDT2.
Super UDT2 is synthetic and very pricey, and if you have a water issue, stay with UDT.
They are about the same in cold climate
I've a big fan of Mystik JT-5 it's cheaper, but performs excellently in cold climate, I'm not sure if you can get it in Canada?