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2019 Sport CVT
960 Posts
My first thought was that this test was bogus as the circumference isn’t going to change. But then does it? If it doesn’t then indirect TPMS wouldn’t work…

"Indirect TPMS do not use physical pressure sensors but measure air pressures by monitoring individual wheel rotational speeds and other signals available outside of the tire itself. First generation iTPMS systems utilize the effect that an under-inflated tire has a slightly smaller diameter (and hence higher angular velocity) than a correctly inflated one. These differences are measurable through the wheel speed sensors of ABS/ESC systems."
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