Upsizing Wheels and Tires With The Organic Mechanic
Posted April 25, 2012 9:23 AM
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 The Organic Mechanic to learn more about how you might upsize your wheels or tires. You'll find us at 568 Haywood Rd in Asheville, North Carolina 28806.
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 The Organic Mechanic 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 The Organic Mechanic 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.
Posted in the Tires and Wheels category
Tire Tread Depth for Asheville North Carolina
Posted April 18, 2012 1:25 PM
So, when are your tires actually worn out? This is a question a lot of us in Asheville North Carolina 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 The Organic Mechanic (just call 828-255-2628) to find out what your requirements are in the Asheville North Carolina 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 Asheville North Carolina, 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 Asheville North Carolina 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.
Sometimes when we talk about exhaust service in Asheville, we think about exhaust pipes and mufflers. And if you can see smoke, or if it’s too loud. But, exhaust service at a place like The Organic Mechanic is really a lot more comprehensive these days.
For example, in the U.S., the federal government mandated catalytic converters for all cars in Asheville in 1976 and on-board emission control computers in 1990. North Carolina and federal emissions requirements have forced manufacturers to come up with much more sophisticated ways to comply with environmental regulations. Cars sold in Canada follow the same guidelines.
So, exhaust service has really become exhaust and emissions service. High-tech computer-controlled emissions devices are now a big part of that. And because it’s so sophisticated, your vehicle manufacturer recommends having your emission system checked out by a qualified technician, like the ones we have at The Organic Mechanic, regularly to make sure everything’s working right – which is usually every six months or 6,000 miles.
If your 'check engine light' comes on while you are driving around the Hendersonville area, especially if it’s flashing, then you need to get your car looked at right away. Chances are it’s an emission related problem. You might have exhaust or emissions trouble if your car is hard to start, runs rough, or if it’s noisy or smoking.
So let’s review the exhaust system. Everything starts with the exhaust manifold. That’s the part that attaches to the engine and collects the exhaust from the cylinders and directs it into the exhaust pipe.
The exhaust gaskets help seal the connection with the manifold and other joints along the way. Now, if the manifold is cracked or loose, or a gasket is leaking, then dangerous gases could escape into the passenger compartment, where you ride. Carbon monoxide can be deadly, so it’s important that your exhaust system doesn’t leak.
The exhaust pipes connect the various components. They can rust or be damaged by a rock, so they need to be inspected periodically.
Next comes the catalytic converter. This part actually looks like a muffler. It changes chemicals that are dangerous to your health, and to the local North Carolina environment, into harmless carbon dioxide and water. Now it doesn’t require any maintenance itself. But eventually they wear out. If it has, you’ll probably find out when your car fails an emissions inspection.
Now the muffler. Its main job is to quiet engine noises. Mufflers work by either absorbing or baffling sound. And you can actually customize your car’s sound with different mufflers – which is pretty cool because you can change the look of your car, and the way it sounds.
Rusted or road-damaged mufflers can actually leak and they need to be replaced right away. The exhaust system is attached to the car by a series of hangers and clamps that hold the system in place. And when these hangers come loose or break then hot exhaust components can touch and melt wires, hoses and lines. Just think of the damage a hot curling iron can do – but worse. It’s not good to have that waving around.
And finally, we end at the tailpipe. Appropriate name. This is the final outlet for the exhaust. And one other component is the oxygen sensor. It monitors the oxygen content of the exhaust so the engine-control computer can adjust the fuel-to-air mix to keep the car running right.
We hope this hasn’t been too 'exhausting' of a discussion, but these things impact everything from life and death safety due to exhaust leaks, to just fine-tuning the sound of your ride. And talk with your service advisor at The Organic Mechanic if you feel you need any of these items inspected on your vehicle, because a quick look can sure save a lot of pain down the road.
We all know that under inflated tires wear out more quickly. Under-inflation is also a major cause of tire failure. More flats, blow outs, skids and longer stopping distances are all results of under-inflated tires.
It's hard to tell when a radial tire is under-inflated. If your manufacturer recommends 35 pounds of pressure, your tire is considered significantly under inflated at 26 pounds. The tire may not look low until it gets below 20 pounds.
Uncle Sam to the rescue! A new federal law requires manufacturers to include a Tire Pressure Monitoring System - or TPMS system - in all vehicles by the 2008 model year.
Some 2006 and 2007 models already have TPMS. The system is a dashboard mounted warning light that goes off if one or more of the tires falls 25 % below the manufacturer's pressure recommendations.
The law covers all passenger cars, SUVs, mini vans and pick up trucks. The system must also indicate if it has a malfunction. This technology has been used by race cars for years. They are able to head off problems from under inflation by closely monitoring tire pressure on the track. It's up to your car's manufacturer to determine which of many TPMS systems available they'll use to comply with the law.
Obviously, all of this doesn't come free. Government studies have estimated the net costs. Of course, the TPMS system itself will cost something. Maintaining the system will have a cost, replacement of worn or broken parts and tire repair cost increases. The net cost is estimated to be between $27 and $100.
The costs are partially offset by savings in fuel and tread wear. There is also a saving in property damage and travel delay. Also, the government predicts fewer fatal accidents. They estimate there will be between $3,000,000 to $9,000,000 for every life saved.
Your safety has always been a concern of your service center. They want you on the road and accident free. They've traditionally provided things like tire rotations, snow tire mounting and flat fixes at a very low cost. They've been able to quickly and cheaply provide the service, and they pass the low cost on to you as an expression of their good will. That's why they're concerned about how you'll perceive the changes that this new law will force.
Every time a tire is changed: taken off to fix a flat, a new tire installed, or a snow tire mounted, the service technician is now going to have to deal with the TPMS system. Sensors will need to be removed and reinstalled. The sensors will have to be re-activated after the change. And, unfortunately, the very act of changing the tire will damage some sensor parts from time to time - it's inevitable and can't be avoided.
Even a simple tire rotation will require that the monitor be reprogrammed to the new location of each tire. When a car battery is disconnected, the TPMS system will need to be reprogrammed. TPMS sensor batteries will need to be changed and failed parts replaced.
And the service centers themselves will need to purchase new scanning equipment to work with the TPMS sensors and to update expensive tire change equipment to better service wheels equipped with the new monitoring systems.
Service technicians will have to be trained on many systems and new tire-changing techniques. All of this adds up to significantly increased cost to the service center to perform what was once a very inexpensive service for you. So when you start so see the cost of tire changes, flat repairs and rotations going up, please keep in mind that it's because of government mandated safety equipment. Your service center just wants to keep you safely on the road - and it's committed to do so at a fair price. The effects of the new law will take some time to sort out, but it will help you avoid the most common vehicle failure, and possibly a catastrophic accident.
Located in the Asheville area, we service the following communities: Swannanoa, Black Mountain, Weaverville, Mars Hill, Marshall, Biltmore Forest, Fairview, Bent Creek, Avery Creek, Canton and surrounding areas.