Winter tire users rejoice - no TPMS

I had a pleasant surprise with the V60 when I took delivery of the car and installed my winter wheel set. Like many New Englanders, I have a separate set of wheels with winter tires mounted, specifically Dunlop SP Winter Sport 3Ds. All of my previous cars have had a tire pressure monitoring  system (TPMS) in place. This is a nice little feature when driving with stock tires, but I typically don't waste my money on a separate set of sensors for winter. They can cost $30-50 per wheel, like these here. For 6 months out of the year, I would simply put up with the TPMS warning light on my dash.

No such warning light occurred after I installed my winter wheels and tires onto the V60. Curious to know why, I delved into the owner's manual and discovered the following:

The V60 can have a regular TPMS system, or the confusingly-named Tire Monitor (I'll call it TM for short). There's no outward clue on the car, to my knowledge, as to which system you have. How do you check? Go into the My Car menu --> Settings --> Car Settings. If you have an entry called Tire Pressure, sucks for you! You have TPMS and you must now suffer the warning light in wintertime, or pay out the nose for a separate set of sensors, or pay out the nose to have a tire shop swap your tires twice per year, or move to Florida, or crash and die on your all-season tires (and pay out the nose in medical/funeral bills). If you have an entry called Tire Monitoring, congrats! You have TM and you will suffer none of those indignities.

TM must be calibrated with the tires at their correct pressures to begin with. You can do this in the settings menu. It will then use the ABS sensors to track the rotational speed of the tires individually. If one tire becomes low, its diameter becomes smaller, and thus will rotate faster - the ABS system senses this, and warns the user that a tire might be low on pressure. It can determine which tire is low to some degree, but not with pinpoint accuracy, since it's indirectly measuring pressure.

The benefit of this whole thing is that cold-weather drivers who use TM don't have to suffer an annoying warning light on their dash for the entire winter. Or move to Florida. Thank goodness.