Tire Load Rating Importance

How significant is it to change from a tire with a load rating of 97 to one with a load rating of 91, and are there associated safety risks? I had a blowout on the expressway yesterday with my 2006 Saab 9-3 Sportcombi (wagon). For safety purposes, I decided the best course of action was to replace all 4 tires. Rather than replacing with original equipment tires, the tire store recommended another high performance tire that was a better performer at a lower cost. I agreed to this change, not knowing that the new tires had a lower load rating (91 vs 97). The store has offered to replace the tires with the orig equip ones, with me paying the differential cost. Should I make the change?

If were me, I would.

Hmmm…Let’s see. You had a blowout on the original tires with the correct load rating, and you want to know if it is a good idea to keep the new tires with a lower load rating. If you don’t know the obvious answer to this question, then I am certainly not the person to give the VERY obvious answer to you.

Incidentally, the people who run that tire shop are…irresponsible…to say the least. They have left themselves wide-open for a negligence-based lawsuit when (Not IF) you sustain a blowout at high speed. Trust me–it will happen.

I think you’re a bit off point here and perhaps a bit unnecessarily condescending. The blowout had nothing to do with the load factor. It was due to road construction debris that popped a hole in the tire at highway speed. The answer is not so obvious. The difference between a load factor of 91 (1356 lbs) and 97 (1609) is 253 lbs per tire. For a small wagon that is not used for towing or carrying a heavy load, my question is whether the 253 lb difference is significant or within the safety range, an answer that Saab, the tire store, the dealer and multiple online sources didn’t clarify.

If the gross weight of your wagon, loaded, does not exceed the load rating of the tires, I don’t think you have anything to worry about. If, on the other hand, you customarily load your Saab heavily, then it probably matters.

Many people never even think about load rating, and they don’t have trouble.

If you wish to gamble with your safety, the safety of your passengers, and the safety of those driving in adjacent lanes, I am certainly not going to try to dissuade you from doing what you wish in order to save a few bucks.

Stick to the specifications for the tyres made by the car’s manufacturer. The tyre dealer should have them if you can’t find them in your owner’s manual.

It would be totally foolish IMO to using anything less.

I’d go ahead and make the change and pick up the cost, however I also think the tire store misadvised you. In future I’d go elsewhere.

Additionally, rather than “original equipment” ones, which I interpret to they should have a less expensive model tire with the ratings recommended by the manufacturer. Ask.

If you want to know for sure where you stand, load the car and take it to a set of scales and weigh it. If you are under 5400 lbs, you can then determine if the extra 253 lbs per tire is significant and any associated risk. If you never overload your car, then it may not be an issue, on the other hand, 1000 lbs less total capability to me is significant. The wild card is what a max load for you may be fully loaded. We simply do not know what you do with this vehicle, and a question such as this is definitely specific to the car, the owner and what is hauled.

One way to look at it:

If I have an 10 ton load to pickup, am I safer using a 10 ton crane or a 15 ton crane. Obviously, the larger crane is designed to lift more load and would be safer to use, regardless of the load it is trying to pick up.

The same thing applies to tires (or whatever). The more capable a thing is, the safer it is to use. Engineers (including tire engineers) can not accurately assess ALL the circumstances a product will be used in, so the overdesign AND underutilize. In the case of tires, the load rating and the speed rating are indicators of capability - the more, the safer.

The tire shop was irresponsible and reckless (with the safety of your family) for mounting those tires on your vehicle. Go back and have them make it right for free!

Thanks for all the feedback. While the cost of the orig eguip tires was more, my even considering keeping these other tires centered on the fact that they ride significantly better and have an estimated tread life 2 times that of the orig equip tires. I was trying to determine if there is an acceptable safety range for load rating, and if so, do these tires fall within it. It has become clear that there does not appear to be a definitive answer. Given that, I agree the safest and most reasonable course of action is to go with the orig spec tires. I’ve researched online and elsewhere and determined that there is no other viable option other than the orig equip tires. The only other ones available in this size and load rating are ultra performance tires that are significantly more expensive. Given that this is a leased car with 7 months left, these other options do not make sense. The tire store has accepted responsibility and agreed to replace them free of charge with my just paying the incremental difference of the discounted tire price, and that is what I’m going to do.

Thanks everyone!

That’s the safe choice - one other reason to do that, now that you mention it’s going back in 7 months, is to protect yourself from being sued by the future owner if he gets into an accident that he somehow claims was because of the tires. Now that you know they’re the wrong tire, a jury could decide that you should have switched to the correct tire, just as you are doing.

Usually folks are more concerned with going UP in load rating because you tend to see an increase in ride stiffness, and people want to know if it’s worth it. Rarely do I recommend lowering load rating unless it’s by a very small margin. In your case I would not go below a rating of 95. I think you are borderline with a rating of 91 if you ever find yourself with a full car load and the tires are not perfectly inflated. Also some tires are of better quality than others.

That said, if I was going to replace these tires I would recommend passing on the original equipment tires and exploring other options. Usually original equipment tires are chosen with economics in mind-not quality and performance. Explore options at sites like the Tire Rack for ideas.