Archive for the ‘Car Tires and Wheels’ Category
With the recent focus in Byron Center on improving fuel economy, we’ve been told how important it is to maintain our tire pressure.
Everyone in Byron Center 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 Byron Center 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 Wyoming, Michigan vehicle.
Ervine’s Auto Repair
4311 Stafford SW
Wyoming, Michigan 49548
Every vehicle in the Byron Center 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 Ervine’s Auto Repair 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.
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.
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.
So when the temperatures drop below 45 degrees, be sure you have a set of four winter tires for maximum performance in snow, packed snow, ice, wet and dry roads. Your tire professional can help you find the right winter tire for your vehicle and driving needs.