Keeping A Low Profile
by Pat Goss
One of the most changed parts of a modern automobile are its tires. There’s been this continuing evolution in tires, especially when it comes to the profile. See over the years they have become lower and lower in profile.
Twenty years ago, a 75 series tire was quite common. Then it went to 70 and 65 and 60 and so on, where today we have tires that are 60 series that are on average, everyday family sedans. And sports cars, well, they might have something like a 40 series tire.
And when we’re talking about these series, we’re talking about the relationship of the distance from the rim to the tread compared to the width of the tread. So this 40 series tire is, the distance right here is 40 percent of the width of the tire.
Now believe it or not, two tires can share the same width and the same rim diameter. One is a 55 series tire and one is a 40 series. Now what’s the significance of all of this? Yeah, you get better handling and all kinds of things, but you have to be more careful with these tires [40 series], especially when you hit a pothole and you hit it hard. Now sometimes the tire will lose pressure right then and there. It will just become unseated or it will be damaged.
But many times it won’t lose pressure, so that means that you have to examine the tire and the wheel. And that doesn’t just mean the outside, because frequently you’ll find that on the inside there could be damage to both the tire and the wheel. Now if you don’t see anything, you’re probably okay. But if the wheel is damaged and the tire still holds air, that tire needs to be removed from the rim and the technician needs to check it for internal damage. Because you could be riding around on a very dangerous tire. So pay attention to your low profile tires if you want to keep your car safe.