Tires and Wheels - Kams Auto Service Center

Upsizing Wheels and Tires With KAMS Auto

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 KAMS Auto to learn more about how you might upsize your wheels or tires.
You’ll find us at 4878 North Cobb Parkway in Acworth, Georgia 30101.

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 KAMS Auto 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 KAMS Auto 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.

Tire Replacement

You know you need new tires, but you’re not sure what type. You look at a tire to get the size: 225, 50, R, 16, 92, H. All the way to the service center you keep repeating it over and over. You even say it over in your mind while waiting in line. Then you get to the counter and the manager asks what size you need. Then your mind goes blank.

Tire size can be confusing. There’s so much on the side of the tire, and it’s hard to keep straight.

Even though there’s a lot on a tire – if you know what it all means, it’s actually more helpful than confusing. Let’s start with the size number.

For example, let’s say a tire reads: 225 50 R 16 92 H. The 225 part is the width of the tire in millimeters – the width between the sidewalls of an inflated tire with no load. The 50 is the aspect ratio – the ratio of the sidewall height to the tread width. Off-road tires will have a higher number and high performance tires will have a lower number.

The R signifies it’s a radial tire. And 16 is the rim or wheel size in inches.

The 92 is the load rating index – it’s the load carrying capacity of a tire. The higher the number, the more it can safely carry. Your empty vehicle can be safe with a lower number, but you’ll need a higher rating if you routinely haul heavy loads. The next letter is the speed rating. Not all tires are speed rated. The ratings generally follow the alphabet: the further up the alphabet, the higher the speed rating – with the exception of H – it comes between U and V (don’t ask why).

There’s a lot of fine print that you probably need a magnifying glass to read. But there are a couple of other large print items of interest. One is the tread type: highway, mud and snow, all season, severe snow, etc.

And then there’re the Uniform Tire Quality Grading System markings. The first is a tread wear index. 100 is the base line – a lower number is poorer and a higher number is better. All things being equal, a tire rated 200 would wear twice as long, on a government test track, than one rated at 100. These wear grades are only valid within a manufacturer’s product line – you can’t compare with other manufacturers. And it’s important to note that a lower rating might be just what you want – a high performance, sticky tire has a softer rubber compound and won’t wear as long, but boy, will it take those corners.

The next is a traction grade. This measures the tire’s ability to stop on wet pavement in government tests. A – the best, B – intermediate, C – acceptable.

Temperature grade measures a tire’s resistance to heat build up in government tests. A, B and C – from best to acceptable.

It’s safe to go with the original equipment recommendations that came on your car. But if you want to make adjustments, you’ll now be better equipped to communicate with your tire professional.

Wheel Bearings

Let me start by saying that your wheel bearings keep the wheels on your vehicle. Did that get your attention? In this article we’ll discuss more about wheel bearings and how you can keep them doing their very important job while you drive around Kennesaw Georgia.

Come see us at: 4878 North Cobb Parkway Acworth, Georgia 30101

Wheel bearings are pretty simple parts. They’re made of high quality steel and are engineered to last 100,000 miles or more if properly cared for. The bearings do two very important jobs: First they allow the wheel to freely rotate with as little friction as possible. Second, they support the weight of the vehicle. For example, if your car weighs 3,600 pounds, each wheel has to support approximately 900 pounds. That’s a lot of heavy lifting over many, many thousands of miles.

Even though wheel bearings are relatively simple, they need to be in near perfect condition to do their job. The bearings are packed with heavy grease to lubricate and protect them. A seal keeps the grease in and water and dirt out. It’s when the seal starts to leak that problems begin. The grease can become contaminated; causing the wheel bearings to overheat and ultimately fail.

The first sign that your wheel bearings are in trouble is an unusual noise coming from a wheel. It could be a chirping, growling, rumbling or a cyclic sound. The noise could get louder or even disappear at certain speeds. Your technician at KAMS Auto can inspect for bearing wear by lifting the vehicle and checking for play in the wheel.

Now some wheel bearing assemblies are factory sealed. That means that they cannot be serviced – they can only be replaced. Those that aren’t sealed can be serviced on schedule. The bearings are removed, cleaned and inspected. If the bearings are still good, they’re re-installed – if not, they’re replaced. They are then packed in grease and a new seal is installed.

If your vehicle has a factory sealed wheel bearing assembly, the entire assembly needs to be replaced when trouble arises. Unfortunately, the parts are pretty pricy – but they usually last about 150,000 miles as long as the seals hold up.

Now, even a good seal cannot keep out water that’s exerting pressure on the seal. So if you’ve driven through hub deep water your bearings should be cleaned and repacked if they’re serviceable. If you have factory sealed bearings, you just need to watch for signs of premature failure.

If your wheel bearings can be serviced, your owner’s manual will recommend an interval, usually around 30,000 miles.

Now, if you have any sort of trailer, don’t forget its wheel bearings. They probably need to be serviced even more frequently. This is especially true for boat trailers that are used to launch the boat by backing it into the water. These should be serviced every year, usually at the end of the season so that the bearings don’t have the opportunity to sit and rust all winter.

So what happens if wheel bearings fail? Well, the wheel can literally fall off the vehicle. I don’t need to tell you how bad that could be. So check with your service advisor at KAMS Auto and see if your vehicle’s wheel bearings can be serviced and when it’s recommended. Listen for warning signs. If you’ve been fording streams or puddle surfing after rainstorms, be especially vigilant.

Come by KAMS Auto for a wheel bearing inspection, or for break service. Call for an appointment at 770-529-0330

Selecting New Tires and Wheels

Some of us just love tires. All those little rubber hairs on new tires and the smell is wonderful. We live in a great time for tires. No matter how you drive, where you want to go or the look you’re after; there is a tire for you.

The same is true about wheels. The hardest part is choosing from the thousands of wheels available.

We may not be able to help with that, but we can help you get some things in mind before you consult with your Acworth tire professional. Let’s start with function and think about how you drive.

For example, maybe you have a large SUV but you don’t drive off-road, so an off-road tread isn’t important. Also, because you are not out bouncing over rocks in the Georgia backcountry, you don’t need a high profile tire to protect your rims. So that means you can probably go with the low-wide look.

If you have a winter season with rain and snow or if you find you need better ice and snow performance, they make great, high-performance snow tires that won’t make it look like you are driving a tractor.

There really are a lot of options for any given vehicle. You will find it very helpful to have a discussion like this with your Acworth tire pro when you need new tires. You can find the best solutions for your driving needs and to make improvements in ride or handling.

Picking a wheel that is the same size as what you are now running is pretty simple. But, it gets trickier if you want to upsize. Just get some help when you go bigger. All that tire and wheel still needs to fit in the available space. You do not want your tires to rub when you turn or hit a bump. You also need to make sure your brakes and suspension bits will fit with your wheel of choice. It doesn’t matter how great your car looks if it’s not drivable.

Taller, wider wheels and tires probably weigh more than your stock shoes. And it’s “unsprung” weight – that has a big impact on brake performance. The upsized shoes increase rotational inertia – if you go too big you may need to upgrade your brakes to compensate.

Another possible problem is an inaccurate speedometer. This happens because the number of rotations can change with the new wheels. Fortunately, speedometers and odometers are all controlled by the engine computer; so it is simple to get it reprogrammed and compensate for the bigger tires.

No matter what you are after: low cost, long life, high performance, traction or stunning good looks, your wheel and tire professional at KAMS Auto in Acworth, Georgia can help you identify your needs and give you a custom fit. With all the options available, you don’t have to compromise. There is a tire out there with your name on it!

Tire Tread Depth for Acworth Georgia

So, when are your tires actually worn out? This is a question a lot of us in Acworth Georgia 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 kams auto (just call 770-529-0330) to find out what your requirements are in the Acworth Georgia 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 Acworth Georgia, 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 Acworth Georgia 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.

kams auto
4878 North Cobb Parkway
Acworth, Georgia 30101
770-529-0330

Winter Tires

What type of technology do you use? Do you prefer an 8-track tape or an iPod? When it comes to winter tires, much of the public’s perception dates back to when 8-track was the best way to listen to the Bee Gees.

Twenty years ago, winter tires differed from highway tires only in their tread design. We called them snow tires back then and they had big, knobby lugs that were designed to give good traction in deep snow. They had the same rubber compound as regular tires and they weren’t very good on ice, packed snow or wet roads. They were not even very good on dry roads. They really helped in deep or loose snow, but they did a poor job the rest of the time. They were loud and rode hard. You couldn’t wait to get them off in the spring.

Then all-season tires started to come along. All-season tires are really a compromise between summer and winter performance. They have acceptable hot weather ride and tread life, and you can get through mild winter road conditions OK. But there are some really good reasons to consider winter tires.

Modern winter tires do a terrific job in a wide range of winter conditions. First of all, below 45 degrees Fahrenheit, regular tires become hard and inflexible. That means they don’t provide the road grip you need. Even if you don’t live somewhere with a lot of snow, but it still gets below 45 degrees in the winter, you will be safer with winter tires.

In addition, they are specifically designed to more effectively move snow and water. That’s the key to traction on ice, packed snow and wet roads. They use a micro-pore compound that allows the tire to bite into ice and snow. They also use wider grooves that run around the circumference of the tread to expel snow from the tire better. The lugs and grooves on winter tires have a special shape that throws the packed snow out of the tread as the tire turns. The tread is then open when it comes back in contact with the road and can provide good traction.

Winter tires also have a lot of sipes. Sipes are thin slits in the tread. The edge of the sipes grab ice and packed snow to provide tons of traction and to expel water and slush out of the tread. winter tires have a rounder casing to cut into the snow’s surface. The treads on regular summer tires can actually get packed with snow instead and become very slick. winter tires offer 25% to 50% more traction than all-season tires. And when it comes to stopping power, all-season tires take 42% longer to stop than winter tires. Sometimes that’s the difference between getting home safely and spending the night in a snow bank.

Now back when the 8-track was king, you just put snow tires on the drive wheels. That worked out OK because the rubber compound was essentially the same. Now, winter tires provide so much more traction than all-season or summer tires, that there’s a huge difference between the traction at the front and rear ends of the car if you only put winter tires on the drive wheels.

For example: if you take a corner on an icy road and the rear end starts to slide out, essentially the rear is trying to pass the front because it’s going faster. If you have high traction winter tires only on the front, they are going to be much more effective at transferring cornering grip and stopping power to the front wheels. This will actually cause the rear end to whip out even more.

That’s why tire manufactures instruct their dealers that they must install winter tires on the rear wheels as well whenever they put winter tires on the front end of any vehicle. It’s a major safety concern. It’s strongly recommended that winter tires be installed on all four wheels on rear wheel drive vehicles as well. The front tires do most of the steering and braking work – it only makes sense that you provide the front end with the best traction you can.

People often assume that if they have four-wheel drive or all-wheel drive they don’t need winter tires on all four wheels. Would you intentionally disconnect the four-wheel drive in poor road conditions? Of course you wouldn’t, but that’s essentially what you do if you only put winter tires on one end. It only makes sense to have the same level of traction and control at all four corners.

The province of Quebec in Canada has issued a law requiring all passenger vehicles, taxis and rental cars with Quebec license plates to install a full set of four winter tires between November 15th and April 1. It’s that important.

Many modern cars have traction control and anti-lock brakes so people may think that they don’t need winter tires. But you need traction to accelerate, steer and stop. The tires provide the traction so that the traction control and anti-lock brakes have something to work with.

Look for tires with the symbol of a mountain with a snowflake in it. This means the tire complies with the severe snow standard. All-season tires will have an M&S, for mud and snow, on the sidewall.