Tire basics: sidewalls, pressure, and DOT age
Use this hub to answer connected tire questions in the right order: identify what the sidewall markings mean and how two sizes compare, find the vehicle’s recommended pressure, decode the DOT manufacturing date, and put tire age in context. The guides carry their citations; the calculators handle the arithmetic without replacing an inspection.
How do I read a tire sidewall?
Decode size, load, speed, construction, and the other markings without treating the sidewall maximum as the car's target pressure.
OpenCompare two tire sizes
Once you can read the size on the sidewall, use the tire size calculator to compare two sizes: overall diameter and the speedometer difference.
OpenWhat tire pressure should I run?
Find the vehicle placard, understand cold pressure, and separate the vehicle recommendation from the tire's maximum rating.
OpenWhy is my tire pressure light on?
Tell a solid light from a flashing one, find the low tire, add air at a gas station or at home, and see why the light can stay on after you fill up.
OpenHow old is this tire?
Locate the DOT date code, read its week and year, and understand why age is one input in a replacement decision.
OpenDecode a DOT date code
Enter the final four digits of a DOT code for an immediate manufacturing-week and age calculation, with limitations shown.
OpenMove from diagnosis to maintenance
An inflator does not determine the correct pressure—the vehicle placard does. Once you have that number and have inspected age and condition, use these paths for the hardware decision.
Choose a tire inflator
After finding the placard pressure, compare cordless and 12V inflators by power source, shutoff behavior, and storage fit.
Open ranked optionsRestore wet-weather visibility
If the maintenance check extends beyond tires, diagnose streaking before replacing a blade that may not be the cause.
Open ranked optionsSee the DriveScored methodology for how product evidence and editorial rank are separated.