You just put the spare tire on your vehicle and now you’re trying to figure out where and when you can take your vehicle in to get a new full-sized tire. When you’re driving on a spare tire it’s all about the 50/50 rule, but there’s a little more to it than that.
We’ll break down everything you need to know about spare tires and how to care for yours here.
Identifying Your Spare Tire
When you’re looking at your spare tire, you need to figure out if it’s a donut-style or a full-sized spare tire. The good news is that it’s usually pretty easy to tell the two apart. If the tire looks just like all the other tires on your vehicle, you have a full-sized spare.
But if the tire is significantly smaller, then you have a donut-style spare tire. You can also look at the sidewall of the tire. If you have a donut-style spare tire there will be plenty of warnings there. For starters, they’ll tell you not to exceed 50 miles per hour.
Once you know what kind of spare tire you have you can quickly determine how long you can safely drive on it.
How Long Can You Drive on a Spare Tire?
When you’re driving on a spare tire you want to remember the 50/50 rule. You should drive no more than 50 miles and no faster than 50 miles per hour. This rule is specifically for donut-style spare tires, if you have a full-sized spare tire in your vehicle then this is not the rule.
It might not seem like much, but you need to remember that donut-style spare tires are there for emergencies only. They’re so you don’t end up stranded on the side of the road and can get to a tire shop to get a new tire on your vehicle.
However, if you have a full-size spare in your vehicle, it’s no different than any of the other tires already on your vehicle. If it’s at the right tire pressure and in good condition, there’s really no limit to how long you can drive with it on your vehicle.
What Happens if You Drive on a Spare Tire Too Long
There are a few different issues that can come up if you drive on a spare tire too long. For starters, you can blow out the spare tire. And since the spare tire is the spare this means you won’t have another tire you can swap it out with.
Second, a donut tire is significantly smaller than the other tires on your vehicle. While that might not seem like a huge deal, it can affect performance in both cornering and braking.
Finally, while it’s rare, driving with a spare tire on your vehicle for too long can actually lead to problems in your vehicle’s transmission and differential. This is especially true in all-wheel-drive vehicles. If you have an all-wheel-drive vehicle, we highly recommend disabling the all-wheel-drive system if you can while using a spare tire.
Can You Reuse a Spare Tire?
If there’s still enough tread on the tire and it’s still in good shape, you can absolutely reuse it. However, keep in mind that the miles you have on the spare tire the first time still count if you need to use it again.
So, if you put 25 miles on the spare tire the first time, the spare tire only has 25 miles of life left. You really don’t want to exceed that mileage limit or else you risk blowing out the spare tire and ending up stranded on the side of the road with no spare tire to switch to.
What Tires Should You Replace?
If you’re putting a spare tire on your vehicle, it’s because you have a flat. And if you have a flat, it means you’ll need to purchase a new tire soon.
But should you purchase more than one tire, or should you just replace the flat tire? Well, it all depends on how much tread is still on the other tires.
If you have more than 70 percent tread life on the three remaining tires, it’s perfectly fine just to replace one tire. However, if you have between that 50 and 70 percent tread life remaining, replace both tires on that axle and move them both to the rear of the vehicle.
Finally, if you have under 50 percent tread life remaining on the three remaining tires, you should replace all four.
Replacing tires this way allows for more predictable handling, braking, and overall performance, which is a pretty big deal when you’re driving down the road.
How Often Should You Inspect a Spare Tire?
When was the last time you checked the spare tire on your vehicle? Just like the tires on the outside of your vehicle, the spare tire can suffer from changes in tire pressure and the rubber can break down over time.
That’s why we recommend inspecting your spare tire once every 10,000 miles or whenever you rotate the tires on the outside of your vehicle. Check the air pressure and for any cracks or damage to the tire.
While it might be a little inconvenient for you, inspecting the spare tire routinely ensures it’s in good working order and is ready to go when you need it!
How Often Should You Replace a Spare Tire?
Just like the tires on the outside of your vehicle wear out, so does the spare. Once you put 50 miles on the spare tire you should replace it, but you also should replace it after ten years whether you put it on your vehicle or not.
That’s because the rubber compounds that make up the tire will break down over time. This will cause the tires to dry rot, and the dry rot starts on the inside of the tire. When you put the vehicle’s weight on the old spare, the dry rot can cause the rubber to fail and leave you completely stranded without a functioning spare.
How Much Do Spare Tires Cost?
Now that you know you should replace your spare tires every ten years at a minimum, it might be time for you to get a new spare tire for your vehicle. If it’s time for you to replace the spare tire you should expect to spend between $50 and $300 for a new one. It all comes down to the size of the spare tire you need.
Most car spare tires cost between $50 and $150, while spare tires for larger vehicles like trucks can run closer to the $300 mark.
Read more: How Much Does It Cost To Patch a Tire?