Tires: Honda Civic tire load ratings, low profile tires, honda civic ex

Question
Hi, I have a question regarding the tire load ratings for my 2000 Honda Civic EX. My owner's manual states that the load rating for my tires should be 85S. However, when I purchased the car used, it was running on low-profile tires with a load rating of 80V. When I got new tires, the store told me those tires were fine, and I have never had any problems with them since. However, recently I got a flat (rear left) and had to get a new tire at a different store. They said that my tire had too low of a load capacity, and sold me one at 88Y. When I got back to my regular store, they told me that the tire I had previously was indeed fine, and that I didn't need that new tire. Who is right?

Answer
John,

This is a fairly complicated issue, so if this sounds less than scientific, I hope you will understand.

The vehicle engineers specified a certain load carrying capacity for the tires they provided for the vehicle.  They are required by law to place a sticker indicating what that selection was, so they take this very seriously.  After all, this is so distinct and specific that if they make a mistake, the lawsuits that would result would be fairly easy to win.

Not to mention that there are many people at the vehicle manufacturers who check and double check what decisions are made about the vehicles.  Not to say mistakes aren't made, but with the literally thousands of vehicle affected by a single decision, a mistake has a huge affect.  So a lot of testing and discussion takes place, and the mistakes are rare enough to be note worthy when bad ones are made.  We call them recalls.

By contrast, the store didn't have an engineer look at the tire selection they made - nor did they write down what they had decided and posted it on the car for everyone to see.  No one checked that work, nor is anyone being held responsible for it.  

The odds of a tire failing are fairly low - let's say 1 out of 100,000 - so even if the decision resulted in a 100 times increase in risk, the failure rate would still be fairly low, so the tire store personnel's risk is low.  The problem is that the 1 guy out of 1,000 who experiences that failure also becomes part of a statistic that includes fatalities.  Vehicle engineers are very much aware of this statistic, so are very cautious.  Tire store personnel probably would blame the tire manufacturer.

I have over 30 years in the tire business and I will rarely second-guess a vehicle engineer's decision concerning tire load carrying capacity.  I think you should do the same.