Tire Inspection Guide: How to Check Tire Pressure and Tread
Tire Inspection Guide: How to Check Tire Pressure and Tread
Tire inspections are one of the simplest ways to improve road safety, protect your vehicle’s handling, and avoid expensive surprises.
Whether you’re:
- shopping for a used car, or
- maintaining your current vehicle,
regularly checking tire pressure and tread depth helps you reduce blowout risk, maintain traction in wet or icy conditions, and improve fuel efficiency.
What this guide covers
- How to check tire pressure (and what to do if it’s off)
- How to check tire tread (including quick Canadian coin checks)
- Common tire wear patterns and what they usually mean
- When to replace tires (and when to get a professional inspection)
How to check tire pressure
Why tire pressure matters
Correct tire pressure improves:
- braking and stability
- steering response and cornering grip
- even tread wear
- fuel economy
Underinflated tires generate more heat and friction, wear faster, and increase the risk of a blowout.
Overinflated tires reduce the contact patch with the road, which can reduce grip—especially on wet surfaces—and can wear the center of the tread more quickly.
What you’ll need
- a tire pressure gauge (digital, dial, or stick)
- access to an air compressor (gas station, portable inflator, or garage)
- your vehicle’s recommended PSI (usually on the driver’s door jamb sticker or in the owner’s manual)
Important: Use the vehicle manufacturer’s PSI (door sticker), not the maximum PSI printed on the tire sidewall.
Step-by-step: checking tire pressure
Park on a level surface for consistent readings.
Check when tires are cold (before driving, or after the vehicle sits for a few hours).
Remove the valve cap from the first tire.
Press the gauge firmly onto the valve stem until the hissing stops.
Read the PSI on the gauge.
Compare to the recommended PSI on the door sticker.
Adjust as needed:
- If low: add air in short bursts.
- If high: release air in small amounts.
Recheck to confirm the final PSI.
Replace the valve cap securely.
Repeat for all four tires (and the spare if your vehicle has one).
Risks of incorrect tire pressure
- Underinflation: overheating, faster shoulder wear, poor fuel economy, potential blowouts
- Overinflation: reduced grip, harsher ride, faster center tread wear, higher hydroplaning risk
How to check tire tread
Why tread depth matters
Tread is what helps your tire channel water and slush away, maintain grip, and stop effectively. Worn tread increases:
- hydroplaning risk
- longer stopping distance
- loss of control in rain, slush, or snow
If you’re evaluating a used car, tread depth can also tell you whether you’re about to spend money on new tires immediately.
Tools to measure tread depth
- Tread depth gauge (best and most accurate)
- Toonie test (Canada) for a quick check
- Built-in tread wear indicators (small raised bars inside the grooves)
Quick method: tread wear indicators
Most tires include wear bars across the grooves.
- If the tread is level with the wear bar, the tire is at (or near) legal minimum and should be replaced.
Quick method: the Canadian toonie test
A toonie can give you a fast “good vs. worn” check.
- Insert a toonie into a main tread groove.
- If a significant portion of the outer ring remains visible, tread may be too low and you should measure with a gauge.
For best accuracy, check tread depth with a gauge at multiple points around the tire.
Where to measure (important)
Check:
- the center of the tread
- the inner edge
- the outer edge
Uneven numbers across these areas usually signal alignment, inflation, or suspension issues.
Full tire inspection: signs of wear and what they usually mean
Uneven wear patterns
- Worn outer edges: often underinflation or aggressive cornering
- Worn center strip: often overinflation
- One-side wear (inner or outer only): often alignment/camber issues
- Cupping/dips/scalloping: often worn shocks/struts or suspension problems
- Feathering/sawtooth edges: often misalignment (toe issue)
Sidewall and surface damage to watch for
Replace or professionally inspect if you see:
- cracks in the sidewall (dry rot)
- bulges or bubbles (internal damage)
- cords showing or tread separating
- punctures in the sidewall (most sidewall punctures aren’t repairable)
When to replace your tires
Replace tires when:
- tread depth is 4/32” (3.2 mm) or lower (many drivers replace around this point for wet/snow safety)
- you can see cracks, bulges, or cords
- traction noticeably drops in rain or slush
- the tire is 6+ years old (even if tread looks okay), especially if you notice cracking or hardening
If you’re unsure, a tire shop can measure tread depth and check for unsafe damage in minutes.
Conclusion
A quick tire check takes only a few minutes, but it can prevent accidents, reduce operating costs, and extend tire life.
Make it a habit to:
- check tire pressure regularly (especially during seasonal temperature changes)
- inspect tread depth and wear patterns
- address uneven wear early to avoid replacing tires prematurely
If you’re shopping for a used vehicle, tire condition is also a great clue about how the car was maintained—and how much you might spend immediately after purchase.
