A tire 25% below pressure is 3x as likely to be in a crash.
Inflating your tires properly can also save on gas costs!
Get them checked.
Data: NHTSA. 2012. Evaluation of the Effectiveness Of TPMS in Proper Tire Pre
Something I recently found out, don't fill your tires to what it says on the sidewall. There's a sticker inside the drivers door that tells you the correct psi for the tires. The front may be different than the rear.