At AutoNetTV we love doughnuts. So let’s pretend you have three doughnuts right in front of your for our discussion of upsizing wheels and tires. Hey, don’t eat them now – your going to need them later.

Many people want to accessorize their car – you know, make it theirs. One of the easiest ways to get a custom look is to get some new wheels. There are thousands of wheel designs out there to get you the look you want. And for many, that look includes bigger wheels. It used to be that cars came from the factory with 15 or 16 inch wheels. Now 16, 17 and even 18 inchers are standard. And the factories are offering optional wheel packages up to 20 inches or more.

Come in to Kevin’s Car Care to learn more about how you might upsize your wheels or tires.
You’ll find us at 7590 US Highway 61-67 in Barnhart, Missouri 63012.

So let’s talk about what to consider when you want to upsize your wheels. It’s not exactly a do it yourself project, so you need to know a thing or two before you get started. The most important term to know is rolling diameter. The rolling diameter is simply the overall height of your tire. Unless you want to modify your suspension, you’ll want to keep your rolling diameter the same when you upsize your wheels.

Let’s think about those three golden doughnuts in front of you. They’re all about the same size. So if we pretend they’re tires, they would have the same rolling diameter. The doughnut hole is the size of the wheel. Now pretend we’ve made the hole bigger on some. That’s like having a bigger wheel – but the rolling diameter is the same.

It’s important to keep the rolling diameter the same for several reasons. First of all, if the tire is bigger, it might not fit in the wheel well. Next the speedometer, odometer and anti-lock brake system are all calibrated for the factory rolling diameter. In order for your anti-lock brakes to work properly, the rolling diameter must stay within 3% of the factory recommendation. If you ignore that, you run the risk that your anti-lock brakes won’t work properly.

Some cars today have electronically controlled suspension that will be negatively affected by changing the rolling diameter. Let’s think about the doughnuts again. You see, as the size of the wheel gets bigger, the sidewall gets shorter. The tire holds less air, so the sidewalls are made stiffer to compensate.

Low profile tires from top manufacturers use special compounds that give the sidewall the strength it needs without compromising ride quality. As you increase your wheel size, you’ll typically get a slightly wider tire. This means that you have a larger contact patch. The contact patch is part of the tire that contacts the road. Because there’s more rubber on the road, the vehicle will handle better. And braking distances will be shorter. A lot of people with trucks or SUV’s love the extra control.

You do have to watch out that the contact patch isn’t so big that the tires rub in turns or over bumps. What we’re talking about here is fitment. Your tire professional at Kevin’s Car Care can help you get this right. He’ll install your new wheels, add spacers if needed to make sure your brakes fit inside your new wheels, and get you rolling.

Also, if you drive off-road a lot, you may need a higher profile tire to protect your new rims. And make sure your new tires have the load rating you need if you tow a trailer or haul heavy loads. Again, your tire professional at Kevin’s Car Care knows how to help.

And don’t forget about tire pressure. If you have larger rims, your new tires will hold less air and they’ll need to run a slightly higher pressure. Forget that and you’ll wear your tires out fast. Finally, get an alignment after you get your new shoes. AutoNetTV wants you to safely have the look you want.

With the recent focus in Festus on improving fuel economy, we’ve been told how important it is to maintain our tire pressure.

Everyone in Festus knows that tires wear out, but we all want to make them last as long as possible because they’re fairly expensive to replace. In addition to saving gas, properly inflated tires last longer. Under-inflated tires will wear out more quickly.

Some people in Festus wonder if there is benefit to adding a few extra pounds of pressure when they fill up their tires. But actually, there isn’t. In fact, there are very good reasons not to over-inflate your tires. For one, the middle of the tread will wear unevenly because the full tread is not contacting the road properly. That also adversely affects your handling.

Come in and see us about tire maintenance for your Barnhart, Missouri vehicle.
Kevin’s Car Care
7590 US Highway 61-67
Barnhart, Missouri 63012
6364641200

Every vehicle in the Festus area has a sticker on the driver’s side door jamb that tells you the manufacturer’s recommended tire pressure. This recommendation is an integral part of the vehicle’s suspension tuning. A lot of engineering actually goes into the recommended tire pressure, so it’s important to follow it.

What else do we need to know about tire maintenance? Tire rotation and balancing are very important. Let’s start with rotation. Because the front tires handle the brunt of turning forces, the shoulders of the front tires wear more quickly than the rear tires. We rotate the tires so that they all get to do some duty on the front and they’ll all wear evenly over their life.

For most vehicles, front tires are rotated to the rear and vice versa. Others recommend a cross rotational pattern. Some vehicles use an asymmetrical tire so those tires need to stay on either the right or left side – it’ll say which on the tire. Some high performance cars have asymmetrical tires and different sizes on the front and rear. These can’t be rotated at all. Your owner’s manual will have details for your car.

How often should you rotate your tires? Your owner’s manual will have a recommendation. Your service advisor at Kevin’s Car Care can do a visual inspection to let you know if it looks like it should be done. The interval is typically around 5,000 miles.

You know, some people don’t think new tires need to be balanced. What they aren’t taking into account is the wheel. Between the wheel and the tire – even a new tire – there’s enough variation to require balancing.

When you add the valve stem and tire pressure monitoring sensors required on new cars, balancing is definitely in order. When a tire’s out of balance, it’s actually hopping down the road. You’ll feel the vibration through the steering wheel if a front tire’s out of balance and through your seat if it’s a rear tire.

Proper wheel balance promotes tire life and increases safety. Historically, lead weights have been attached to the wheel to bring it into balance. Lead gives some environmental concern, so steel weights are starting to be substituted.

Also, always use the same size tire on an axle. Different size tires on the front or on the back can lead to some real handling problems. And tire manufacturers recommend that when you get two new tires, they be installed on the rear because that’s where you need the most traction to avoid spinning-out.

So, when are your tires actually worn out? This is a question a lot of us in Barnhart Missouri ask ourselves. For many, the answer is ‘when they no longer pass a safety inspection’. But waiting that long can have a serious impact on your safety.

The U.S. Federal government doesn’t have any laws for tread depth, but 42 of the states, and all of Canada, do have regulations. They consider two-thirty-seconds of an inch to be the minimum legal tread depth. Two other states, including California, consider one-thirty-second to be the minimum and six states have no standards at all. Call us at Kevin’s Car Care (just call 6364641200) to find out what your requirements are in the Barnhart Missouri area.

Since 1968, U.S. law has required that a raised bar be molded across all tires. When tires are worn enough that this bar becomes visible, there’s just 2/32” of tread left. But does that older standard give you enough safety?

Well, Consumer Reports issued a call to consider replacing tires when tread reaches 4/32”. And the recommendation is backed by some very compelling studies. Now before we go into the studies, you need to know that the big issue is braking on wet surfaces.

We tend to think of the brakes doing all the stopping, but you also need to have effective tires to actually stop the car. When it’s wet or snowy in Barnhart Missouri, the tread of the tire is critical to stopping power.

Picture this: you’re driving over a water-covered stretch of road. Your tires actually need to be in contact with the road in order to stop. That means the tire has to channel the water away so the tire is actually contacting the road and not floating on a thin film of water – a condition known as hydroplaning. When there’s not enough tread depth on a tire, it can’t move the water out of the way and you start to hydroplane.

This is where the studies come in. We think you’ll be surprised. A section of a test track was flooded with a thin layer of water. If you laid a dime flat on the track, the water would be deep enough to surround the coin, but not enough to cover it.

A car and a full-sized pick-up truck were brought up to 70 mph and then made a hard stop in the wet test area. Stopping distance and time were measured for three different tire depths. First, they tested new tires. Then tires worn to legal limits. And finally, tires with 4/32” of tread were tested – this is the depth suggested by Consumer Reports

When the car with the legally worn tires had braked for the distance required to stop the car with new tires, it was still going 55 mph. The stopping distance was nearly doubled. That means if you barely have room to stop with new tires, then you would hit the car in front of you at 55 mph with the worn tires.

Now with the partially worn tires – at the depth recommended by Consumer Reports – the car was still going at 45 mph at the point where new tires brought the car to a halt. That’s a big improvement – you can see why Consumer Reports and others are calling for a new standard.

Now without going into all the details, let us tell you that stopping the truck with worn tires needed almost 1/10 of a mile of clear road ahead to come to a safe stop. Obviously this is really a big safety issue.

The tests were conducted with the same vehicles, but with different sets of tires. The brakes were the same, so the only variable, was the tires.

So, how do you know when your tires are at 4/32”? Well, it’s pretty easy. Just insert a quarter into the tread. Put it in upside down. If the tread doesn’t cover George Washington’s hairline, it’s time to replace your tires. With a Canadian quarter, the tread should cover the numbers in the year stamp.

Now you may remember doing that with pennies. But a penny gives you 2/32” of an inch to Abraham Lincoln’s head. The quarter is the new standard – 4/32”.

Tires are a big ticket item and most people in Barnhart Missouri want to get the most wear out of them that they can. But do you want that much more risk just to run your tires until they are legally worn out? For us, and we would guess for many, the answer is “no”.

Well, Mr. Washington, let’s go out and look at my tires.

Kevin’s Car Care
7590 US Highway 61-67
Barnhart, Missouri 63012
6364641200