Wednesday, May 27, 2015

Tire speed ratings and what they mean

Speed rating. Wow, that sounds cool! But what is it and why is it important to me?

I still use the term speed rating from time to time. More often now, I refer to it as performance rating. In the real world, most people will not drive as fast as the tire is capable of  going. The reason I call it performance rating is simple. By upgrading to a higher speed rated tire, I can improve the handling characteristics of my car without an expensive upgrade. It doesn't mean the car will travel that fast, just that it will be more responsive. There will be less flex in the sidewall when cornering. I upgraded from 'S' rated (up to 112mph) to 'H' rated (up to 130mph)That has suited me just fine
BF Goodrich has a chart that lists most of the different ratings here- (

I work on an island. It is rare to get my car over 50 mph, let alone 186mph. Heck, my car isn't even capable of going safely at the maximum rated speed for snow tires. (around 99mph)

So, why do they have different ratings and why does it matter to me? The handling characteristics, the sidewall strength, the extra support built in to the bead(where the tire mounts on  the wheel.) the additional strength in the center of the tire and the design of the tread. Most higher performance grade tires do not have a mileage warranty and will tend to wear out quicker than one with a lower rating. Most also use a different rubber compound to help with traction.

There are other structural things in the tire that increase its strength and durability. Still, 75mph is plenty for my little car.

There may be an upgrade available on your car. Contact me and I can help look for what is available. I will give you some advice or recommendations based on your specific needs. Feel free to contact me via email-

Tuesday, May 26, 2015

National Tire Safety Week, May 24th thru May 30th

There is a lot of information out there about tires. During National Tire Safety Week, I will try to touch on 1 topic per day.

I was on YouTube and found several good videos to help demonstrate tread depth & air pressure. Pirelli has a good one that shows you where to find the proper tire pressure for your vehicle, and how to tell when your tires are almost worn out. 
DO NOT GO BY THE PRESSURE ON THE SIDE OF THE TIRE! That is a maximum setting and it will adversely affect your handling, possibly even causing a blow out. For best performance, follow the vehicle manufacturers tire pressure specifications.

One thing that I try to explain to my customers about tread depth is what it really means.I think that it is really important to understand why there are various grooves and channels in tires. The grooves that go around the tire 360 degrees are designed to help evacuate water. When a tire is new, the tread depth is usually between 8/32" and 10/32" deep. That gives plenty of room to move the water thru the grooves. The smaller blocks of tread aid in traction and will help evacuate water to the sides of the tires. When a tire is worn out, there is not as much room to channel the water. This can cause hydroplaning on wet roads.

I will usually recommend tires be replaced when there is about 4/32" remaining. There is still enough room to move the water and prevent hydroplaning.

Next up.......... Speed ratings on tires