How Tire Speed Ratings Affect the Safety of Your Car

When it comes to tires and the safety of those inside the vehicle, there’s a lot riding on the letters of the alphabet.

All tires have a speed rating, and those ratings determine how fast the vehicle can safely travel on those tires, from about 75 mph to 186 mph.

An “H” rated tire, originally known as a high performance tire, will allow a car to go up to 130 mph.

A customer recently came into our shop and told us his Nissan was pulling to the right when driven. A perfect candidate for an alignment, we pulled the tires from the car and noticed two different tires on the front and two matching tires on the rear. The right front tire, a T-rated tire capable of traveling up to 118 mph, and an S-rated tire that can go up to 112 mph.

The matching rear tires installed by the factory were faster, H-rated tires.

It was clear that the tires were causing the alignment issue, but we also know having three different speed rated tires on the same vehicle is an issue that impact the car’s overall ability to run safely. The higher “H” speed-rated tires originally installed on the rear of the car were the right tires for the vehicle.

So, how did the car come to have tires with three separate safety ratings? The customer told us a local shop that deals in used tires put them on the car. Afterward, the customer called the tire shop and was told “tire ratings don’t matter.”

We couldn’t disagree more.

“As professionals, we are counted on to provide expert opinions and advice based on facts and supported by experience,” said Rich Campbell, manager of Hometowne Auto Repair & Tire.

“The customer’s safety and security was compromised by a shop that first installed the incorrect tires with different speed ratings,” said Campbell.

Hometowne put on new tires to match the speed ratings of the rear tires, and that not only fixed the alignment problem, it allowed our customer to drive away with four evenly matched speed rated tires making for a safer drive on the road.

So the next time you’re due for new tires, or you’d like to make a tire upgrade, make sure you talk with our technicians about the speed rating of your current tires, and how a higher speed rating could improve your vehicle’s performance.