What’s in a Number? (What Tire Numbers Mean)

You’ve probably never paid much attention to the writing on the sides of your tires, but they contain a wealth of information.  There’s a long combination of letters and numbers that can tell you a whole lot about what tires your vehicle was designed to be riding on.  Let’s check out this example found on an SUV: P245/70R17 108T.

The first letter, P, means it’s intended for passenger vehicles.  If there’s no letter, it means it’s a metric tire.  If there’s an LT at the beginning or end that means a tire designed for light trucks.

Moving on to our example, the 245 shows how wide the tire is in millimeters from sidewall to sidewall.  The number that follows in our example, 70, means the height of the tire is 70% of its width.  The letter after that in our example, R, describes the type of tire (on this vehicle, radial).  Following that is the diameter in inches, in our SUV example, 17 inches. 

How much load the tires’ sidewalls are designed to take is what that next number is all about (108 in our example).  The higher the load index, the more weight the sidewalls can take.  And the last letter is the speed rating of the tire, in our example, T.  The further along in the alphabet that letter is, the higher its speed rating.  So now you know what those letters and numbers mean.  But why are they important?

When you are getting ready to replace those tires, those numbers are telling you what the original equipment was when your vehicle was new.  Sticking with the same rated tires is always a good idea.  If you don’t know what you’re doing, trying different sized tires and wheels can cause real issues when it comes to performance and safety, considering all the computerized systems now found on vehicles.  When in doubt, consult your service advisor when it comes to buying new tires.  He or she knows what those tire numbers and letters mean… and a whole lot more.

Autotronics of St. Peter
111 Jefferson Avenue
St. Peter, MN 56082
507.934.9290
http://autotronicsstpeter.com

Automotive Tips from Autotronics of St. Peter: Brake Noise

Your brake pads are the important parts that rub against the rotor (or disc) to slow and stop your car when driving in St. Peter. They eventually wear down.

When your pads are worn too much, they won’t stop your vehicle as well. When the friction material is worn away, metal parts of the pad are exposed and you’ll hear a squeal or grinding sound.

That’s when St. Peter drivers should replace their brake pads at Autotronics of St. Peter. Not only will new pads restore your stopping power, but replacing them on time will prevent damage to the rotor.

If your brakes are making noise, ask your Autotronics of St. Peter service advisor to inspect your brakes. Addressing problems early will restore your safety and prevent expensive brake damage.

Autotronics of St. Peter
111 Jefferson Avenue
St. Peter, MN 56082
507.934.9290
http://autotronicsstpeter.com

The Red Menace (How to Deal with Rust)

Rust.  It’s worse if you drive in places that use salt on the roads in winter, or if you spend time driving near a body of salt water.  But any vehicle has to deal with rust after years on the road.  And it’s not just that rust can eat away your vehicle’s body and fenders.  It can be a real problem around your suspension, drivetrain or any place where there’s metal.

Rust takes its time.  You don’t see it until it’s already done its dirty work.  It can wreak havoc with your electrical system.  Sure, vehicle manufacturers do their best to keep it to a minimum, but especially with road treatments like brine around, their task is a difficult one.

The one spot everyone notices is in the paint.  You see a little bubbling under the once-smooth surface.  By the time it bubbles, it’s well involved in rotting away that spot of your vehicle.  You wouldn’t believe how just a little thing can start the process on its way.  A stone chips the paint down to the metal, moisture and salt reach the steel and rust is off and running.  It could be a scratch in the paint, a little dent, acid from a parking garage, tree sap, you name it.  If you spot it, show it to your service advisor because rust can be more than a cosmetic problem.  It can be a safety issue.

While you can see the rust destroy your vehicle’s body, you can’t see it destroying your engine.  But it can.  It can eat away at such areas as air intakes or the exhaust system.  Not only can it reduce performance, but also it can disable electrical connections.  In this day and age where just about everything in your vehicle has a computer component to it, just a small electrical problem can strand you at the roadside.

Corrosion can attack your vehicle’s chassis or frame, and they are what provide the structural strength and stability for everything attached.  Think powertrain, suspension, axles, window frames. The list goes on and on.  Structural integrity is vital to safety, so the stakes are high. 

Now you can see why rust damages more than just the good looks of your vehicle. There’s one thing to remember about corrosion – much of it is only visible from underneath the vehicle.  When you bring your vehicle in to Autotronics of St. Peter for service, our technician can look for any problems from that important vantage point.  It’s always a good idea to point out any spots that you think might spell trouble.  That way you can stay ahead of it and beat rust at its own game.

Autotronics of St. Peter
111 Jefferson Avenue
St. Peter, MN 56082
507.934.9290
http://autotronicsstpeter.com