Tire maintenance basics
When should I replace my tires and how do I know if they're safe?
Projekt-Plan
Why: Rubber degrades over time regardless of use, increasing the risk of blowouts.
How:
- Locate the 'DOT' string on the tire sidewall.
- Find the last 4 digits (e.g., 1223).
- The first two digits are the week (12th week), and the last two are the year (2023).
- Replace tires older than 6 years (recommended) or 10 years (maximum).
Done when: The manufacturing date of all four tires is known.
Why: Adequate tread is vital for water displacement and preventing aquaplaning.
How:
- Use a depth gauge or a 2-Euro coin (the silver rim is approx. 4mm).
- Measure in the center and outer grooves.
- Ensure at least 3mm for summer tires and 4mm for winter tires for optimal safety.
- Note that 1.6mm is the absolute legal minimum in most regions.
Done when: Tread depth for all tires is measured and recorded.
Why: Structural defects like bulges or deep cracks can lead to sudden tire failure.
How:
- Run your hand along the sidewall to feel for 'bubbles' or bulges.
- Look for 'dry rot' (fine cracks in the rubber) caused by UV exposure.
- Check for deep cuts that expose the internal metal or fabric cords.
Done when: All tires are visually cleared of structural defects.
Why: Uneven wear indicates mechanical issues like poor alignment or suspension problems.
How:
- Compare the inner and outer edges of the tread.
- Look for 'feathering' (edges feel sharp in one direction) or 'cupping' (scalloped dips).
- If wear is uneven, schedule a wheel alignment immediately.
Done when: Wear patterns are analyzed for alignment issues.
Why: As of late 2024/2025, M+S tires without the Alpine symbol are no longer legally sufficient for winter conditions in many European countries.
How:
- Look for the 'Three-Peak Mountain Snowflake' (3PMSF) icon on the sidewall.
- Ensure all-season or winter tires carry this specific symbol.
- Avoid driving in snow/ice if only 'M+S' is present without the snowflake.
Done when: Winter legality of current tires is confirmed.
Why: Summer tires lose grip below 7°C (45°F), while winter tires wear excessively in heat.
How:
- Plan to switch to winter tires in October (O).
- Plan to switch back to summer tires around Easter (O - Ostern).
- Book appointments 4 weeks in advance to avoid the seasonal rush.
Done when: Seasonal change dates are marked in the calendar.
Why: Using incorrect tire sizes can void insurance and cause failure during technical inspections (TÜV).
How:
- Locate your Certificate of Conformity (COC) or vehicle registration document.
- Compare the allowed dimensions (e.g., 205/55 R16 91V) with the tires currently mounted.
- Ensure the load index and speed rating meet or exceed the requirements.
Done when: Tire specifications are verified against official documents.
Why: You need the exact size to ensure the tire fits the rim and the car's wheel well.
How:
- Read the string on your current tire: [Width]/[Aspect Ratio] [Construction] [Rim Diameter].
- Example: 225/45 R17.
- Note the Load Index (number) and Speed Rating (letter) at the end.
Done when: Full tire spec string is written down.
Why: Modern tire labels provide objective data on fuel economy, wet braking, and noise.
How:
- Look for the EU Tire Label (or equivalent).
- Prioritize 'A' or 'B' ratings for Wet Grip to ensure safety in rain.
- Consider the external rolling noise (decibel value) for driving comfort.
Done when: A tire model is selected based on performance data.
Why: Mixing different brands or tread patterns on the same axle can destabilize the vehicle.
How:
- Order tires from a reputable dealer.
- Ensure all four tires are the same model and have similar DOT dates.
- Opt for generic high-quality brands if premium options are too expensive.
Done when: New tires are ordered or purchased.
Why: Improperly balanced tires cause vibrations that damage the suspension and steering.
How:
- Choose a shop with a dynamic balancing machine.
- Request new valves (or TPMS sensor service) during installation.
- Ensure the shop uses a torque wrench for final tightening.
Done when: Appointment is booked or installation is complete.
Why: Correct pressure ensures optimal contact with the road and prevents overheating.
How:
- Find the pressure placard on the driver's door frame or inside the fuel cap.
- Check pressure when tires are 'cold' (driven less than 3km).
- Adjust for 'loaded' vs. 'unloaded' conditions if carrying heavy cargo.
Done when: All four tires (and spare) are at the correct PSI/Bar.
Why: Bolts can settle after a tire change, potentially loosening over time.
How:
- Use a torque wrench set to your vehicle's specific Nm (usually 110-140 Nm).
- Tighten in a 'star' or 'cross' pattern.
- Do not over-tighten, as this can warp the brake rotors.
Done when: All wheel bolts are verified as secure.
Why: Front and rear tires wear at different rates; rotation equalizes this wear.
How:
- Move front tires to the back and vice versa.
- Follow the pattern in your owner's manual (e.g., cross-rotation for non-directional tires).
- Note: Directional tires (marked with an arrow) can only be swapped front-to-back on the same side.
Done when: Tires are rotated and positions recorded.
Why: Heat and sunlight accelerate rubber aging and cracking.
How:
- Clean tires with water to remove road salt and brake dust.
- Store tires on rims either hanging or stacked.
- Store tires without rims standing upright and rotate them monthly.
- Use a basement or garage, away from electric motors (which produce ozone).
Done when: Off-season tires are safely stored.