[vstolpner]

I would much prefer TPMS to be honest. The ABS based system is not at all sensitive - took my rear tire going to 28 psi before it threw the warning. The time before that it only threw the warning at 26 psi for the front tire. So basically almost 10 psi difference before it notices

The sensors I had in my Impreza told me within 5 psi.

Edit: my X1 currently has. 17" alloys with non RFT tires. I imagine if I have lower profile sidewalls and RFT then the system won't notice a leak until the tires are literally flat.