Can you use a tire with a lower tire load
index than the original manufacture tires??
When you’re shopping for summer tires, there’s more to think about than just size. It’s critical that the load index conforms to your original equipment (OE) specifications too.
Let’s say out of the thousands of tires you can choose from these days, you find a tire you’d like to buy, but it has a smaller load index than your OE specifications.
Can you use a tire with a lower tire load index than the original manufacture tires? The shorter answer is no.
Here’s the reason why.
Why you can’t use a tire with a lower load index than the OE specifications
The engineers who designed your vehicle figured out exactly how much your vehicle could safely carry based on the right tire size and pressure. That amount is a called a tire load index.
A tire load index tells you how much weight a tire can carry at its maximum air pressure. If you take a look at our load index table, you’ll see a load index of 91, for example, translates to a safe carrying capacity of 1,356 pounds or 615 kilograms.
If you’re thinking about up-sizing, you can switch to a tire with a higher load index, because that means your tire will safely be able to carry more weight. But you can never go down.
A tire with a lower load index than your OE specifications can’t properly support the weight of your vehicle and its load (you and your things).
What happens when you use a tire with a lower load index than the OE specifications
When you overload a tire, you can really stress its casing and construction, particularly when combined with driving on hot summer roads. In fact, you could be risking a blowout.
That’s why the Rubber Association of Canada’s guidelines state new tires should never be downgraded in load rating from the tires placed on a vehicle by the car manufacturer.
How to make sure your new tires have the right load index
You should be able to find your manufacturer’s OE specs in your manual or on your door placard, where you’ll see the recommended tire size, load rating and tire pressure