Well, the pressures this morning were 32.5, 32, 32 and 31. I'm surprised how low they were when cold. I thought I'd notice this visually, and didn't realize that the pressure would drop so dramatically with a moderate change in temperature. So the TPM is working just fine and doing what it's supposed to do: Reminding a horse's ass that he needs to check his cold tire pressure regularly. I brought them up to 35 psi and I'll be sure to check them again soon.
