Tires are one of the most important safety factors in a car, yet their condition is often overlooked in the rush of everyday life. We’ve compiled eight key facts that every driver should know before the next tire-changing season.
8 facts about changing tires – save money and yourself
The condition of your tires—let alone tire changes—isn’t something that occupies even an active driver’s mind every day. And with careful, proactive habits, it doesn’t have to. Still, the inevitable tire-changing routine will be here again by spring at the latest, when winter tires make way for summer ones pulled out from storage. But what condition are your winter tires really in as the season comes to an end? And what kind of tires will you rely on for the rainy spring driving conditions ahead?
Tires are one of the most critical safety factors in a car. By giving them a bit of careful thought, you may avoid many costly situations on the road. Small details—like one millimeter of tread depth or half a bar of tire pressure—can determine whether your car stops in time or ends up off the road, and how much driving ultimately costs you.
Review these eight key points about tires and tire changes, and you’ll be driving more safely in our ever-changing weather conditions.
The legal minimum is not a guarantee of safety
The legal minimum tread depth for summer tires is 1.6 millimeters. However, this is merely the threshold to avoid fines—not a guarantee of safety. New summer tires typically have a tread depth of about 7–8 millimeters, and their performance in wet conditions begins to decline well before reaching the legal limit.
Especially in wet conditions, the difference between new and worn tires is dramatic. At 80 km/h, braking distance with worn tires can be several meters longer than with good ones—and in a critical situation, those meters can determine whether you stop in time.
As tread depth approaches the legal minimum, the biggest everyday risk is aquaplaning. Tire grooves are designed to remove water, slush, and snow from between the tire and the road. As tread depth decreases, this ability weakens, increasing the risk of losing contact with the road—and with it, steering and braking control.
Many experts recommend replacing summer tires well before the legal limit, ideally when tread depth reaches around 3 millimeters. Even at that point, wet grip has already significantly declined.
For winter tires, the legal minimum is 3 millimeters. However, for maximum safety, it’s wise to replace them well before that, as grip on snow and slush deteriorates quickly near the limit.
The law defines minimum tread depths—but you define your own standard for safe and worry-free driving.
Better tires: front or rear?
It’s common to see the best tires installed on the drive axle to improve acceleration. However, from a safety perspective, better tires should always be mounted on the rear axle—regardless of whether the car is front-, rear-, or all-wheel drive.
The reason is simple: better rear tires help maintain balanced handling, especially in emergency maneuvers. If the rear loses grip, the car is much harder to control than if the front loses traction.
Mark your tires when removing them so you know their previous position. This makes it easier to rotate them properly next time.
Energy-efficient tires save money
Rolling resistance directly affects fuel consumption—and in electric cars, driving range. A lower price doesn’t necessarily mean lower cost in the long run. Tires with higher rolling resistance or faster wear can become more expensive over their lifetime.
Tires sold in the EU carry an energy label rated from A to E:
A = lowest rolling resistance (most efficient)
E = highest rolling resistance
The difference between A and E can mean about 0.3–0.5 liters per 100 km in fuel consumption.
Special considerations for electric cars
Electric vehicles bring new aspects to tire wear and changes. Their batteries make them heavier, and instant torque can wear tires quickly. Driving style plays a big role in extending tire life.
For example, a Tesla Model 3 weighs significantly more than many comparable sedans, so proper load ratings are essential. Some tires are specifically designed for EVs, focusing on low noise and rolling resistance.
When lifting an electric car, it’s crucial to use the correct jacking points to avoid damaging the battery. Also ensure your jack has sufficient capacity for the vehicle’s weight.
A torque wrench is not overkill
Changing tires yourself can save money, but tools matter. One of the most common DIY mistakes is improper tightening of wheel bolts.
Overtightening can damage threads or rims. Undertightening can lead to bolts loosening—or even a wheel coming off.
Use a torque wrench and follow the manufacturer’s specifications found in the car manual. Also remember to recheck bolt tightness after 50–100 km.
“Tire pressure isn’t that important…”
Even half a bar too low increases fuel consumption and causes uneven wear. It can also negatively affect handling in critical situations.
Always measure pressure when tires are cold. The correct pressure is listed on the car (e.g., door frame or fuel cap), not on the tire.
Adjust pressure based on load—driving alone vs. a fully loaded holiday trip requires different settings.
A “new” tire can be years old
Online shopping makes comparing prices easy, but not all details are obvious. Check the DOT marking on the tire, which indicates its manufacturing week and year (e.g., 3422 = week 34 of 2022).
Rubber hardens over time—even if unused. Winter tires are typically recommended to be replaced after about six years, regardless of appearance.
Not all wear is caused by the tire
Uneven wear can be caused by issues like incorrect wheel alignment. If a tire wears more on one edge, have the alignment checked. Proper alignment extends tire life and improves safety.
Incorrect tire pressure can also lead to uneven wear.
Time to take a look under your car
After reviewing these essentials, it’s time to check your tires. Winter isn’t over, slippery conditions remain, and spring rains will test your tires.
Late winter and late autumn are not the time to push worn tires to their limits—conditions change rapidly, and tires need to perform at their best.
Change your tires in time. You might also find the best deals off-season—summer tires in autumn and winter tires in spring.
Tire changes are not just a twice-a-year routine. They involve important decisions affecting comfort, safety, and costs throughout the year. Don’t assume everything is fine—make sure it is. And if anything about your tires or driving performance concerns you, don’t hesitate to contact Kärkkäinen—we’re here for you.
