What Do The Numbers On My Tires Mean How To Read Tire Sizes
Being able to quickly glance at the sidewall of your tire and determine the tire size your specific vehicle needs can save you time, trouble and money. Even still, not many people know how to actually read a tire size even though its printed right there on the sidewall. As a mix of letters and numbers, its not as easy to read as finding a size 9 shoe.;
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How To Find The Correct Tire Pressure For Your Car
Its very important to inflate your tires with the right tire pressure. If you are driving with the wrong tire pressure, it will cause excessive wear on your tires
- Magnus Sellén
Are you going to inflate your car tires, but you have no idea of what tire pressure is correct for your car?
Having the correct tire pressure in your car is very important, especially nowadays when you have tire pressure monitoring systems. If you run with the wrong tire pressure, you will see warning lights on your dashboard.
In this article, we will go through how you can find the right tire pressure and some other tips about tire pressure.
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What Size Rims Or Wheels Fit My Car
crowd. What wheels willfit on your car? Simple. Just use our shop by vehicle feature and we’ll show options that are guaranteed to fit your vehicle. In some situations, our site will also let you know if a modification to the vehicle is needed for the wheel to fit. This message will appear
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Converting Metric To Inches
There are two ways that tire manufacturers display tire size, inches and metric. How to read tire size in inches is very straight forward.Example A : 33X12.50R15The first number is your overall diameter of the tire. In this example the tire diameter or height is 33 inches tall. The second number represents the width of the tire. In most cases with inch measurement tires the width will have a .50 decimal after the initial number. In example A this reads 12.50, meaning the tire width is 12 and 1/2 inches. The final number simply is the wheel size or diameter of the wheel that the tire will fit on.How to read tire size with a metric measurement is a little more difficult and usually takes a calculator to get exactly right.
How To Use The Tire Size Calculator
Using our tire size calculator is easy:
Want to compare one tire with another one? Then select “Yes” when asked “Compare with another tire?”. The same inputs and outputs will appear for the second tire.
At the end of the tire size conversion calculator, you will see the absolute difference in the diameters of the two tires and the corresponding percentage change. Note that if you are looking to put this second tire on your vehicle, the difference in tire diameter should be no more than 2.5% smaller or larger. If it is larger, the tire might foul the wheel arch of your car, or the tire may be too weighty for the car’s suspension and shock absorbers. Too small a tire size may mean the vehicle’s ground clearance is not practical anymore.
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Tire Size Calculator: What Size Tires Should You Get
If youre considering swapping out your tires for a different size and want a sense of what might work for your vehicle, use our tire size calculator.
How to Figure Out Tire Size
Our tire size calculator converts metric measurements to inches so you can easily compare the diameter, width, sidewall, circumference and revolutions per mile. It will also tell you the difference in tire speed between your comparison tires.
As a general rule, you want replacement tires that are within 3 percent of the diameter measurement of your existing tires diameter assuming your current tires are what your owners manual recommends.
A Note on Accuracy
Our tire size calculator is for general comparison purposes only. We dont recommend that you base sizing or purchase decisions on the calculator alone. A tires true physical size can vary from the dimensions provided by the tire manufacturer, and this tool does not take into account other important application factors like load index and speed rating. These calculations dont account for these variations. The way to be sure your tires are the right fit is to ask your local Les Schwab pro.
Tire Size Explained: What The Numbers Mean
Tire size can be confusing. Some numbers on the sidewall are listed in millimeters while others are inches. Plus, the right size for your car, truck, or trailer can differ depending on where and how you drive.
You can see your original equipment tire size in your owners manual or on the placard generally located on the drivers side door jam. This is the sizing recommended by the vehicle manufacturer.
If youre interested in switching out your tires for a different look or performance, a good place to start is the numbers and other indicators on your existing tires sidewall. Next, have a tire professional help you determine a tire size range that will fit your vehicle and driving needs.
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Where To Find Tire Size
No matter what vehicle you drive, finding the manufacturer-recommended tire size should be easy. The best place to start looking is the ownerâs manual.
Donât worry if you canât locate the manual; you may also find a tire fit guide in these locations:
The driverâs side door jamb
Inside your glove box door
Within your gas tank hatch
Assuming theyâre the proper size, you can find tire size data on the sidewall of your current tires. However, no matter where you find your tire size, you will have to decipher a sequence of numbers and letters.
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Understanding Metric Tire Sizes
Tiresize.com, also says that it can be a bit challenging to figure out what the numbers represent with metric tire sizes. None of the three numbers mean anything without the other two. With the standard system, a 32′ is always a 32′ but, with the metric system, a 265/70/16 is a 30½’ diameter tire, for example, and a 265/75R17 is a 32½’ diameter tire.
The tire size comparison calculator on tiresize.com takes two different tires and calculates the variances between the widths, diameters, sidewalls, circumferences, and revolutions per mile. All you need to do is enter two metric or standard tire sizes and click on the ‘Compare’ button. If you’re looking for tires different to stock size, the calculator includes an additional useful tool. It displays examples of speedometer readings using the first tire, and the real speed you’d be going if you fitted the second tire.
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What Does Microsoft Excel Mean
Microsoft Excel is a software program produced by Microsoft that allows users to organize, format and calculate data with formulas using a spreadsheet system.This software is part of the Microsoft Office suite and is compatible with other applications in the Office suite. Like other Microsoft Office products, Microsoft Excel can now be purchased through the cloud on a subscription basis through Office 365.
Changing Tire Sizes: Good Or Bad Idea
In almost all cases it is recommended that you stick to the factory-size for your car or truck’s tires. This is because many components of the vehicle were specifically designed for that specific size of tire. This mainly has to do with the diameter of your tires.
For example, if you get a larger tire with a larger outside diameter, your car will travel farther before the tire completes an entire rotation. Since your car’s computer determines many things based on tire rotation, such as:
- Speedometer
- Traction control
- Gearing settings
A change in tire diameter means that incorrect information is going into your car’s computer. Your car’s computer relies on correct information from the tires in order to respond well in emergencies. For example, over-sized tires could make your anti-lock brakes fail to engage properly.
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The Different Tread Patterns
The tread pattern is a huge factor in choosing the right tire for your vehicle. The tread pattern can have a great impact on traction, as well as in durability and handling. If you also want a smooth, noise-free, and comfortable ride that may also impact your cars fuel efficiency, then you need to understand more about the three available tire tread patterns to choose from.
1. Symmetrical
This type of pattern normally has a uniform design. This means if you make a lengthwise cut of the tire along the grain to have two complete tires, both the right and the left would have an identical tread design. This is the reason why it is named symmetrical tread pattern.
2. Asymmetrical
Now if you slice a tire with an asymmetrical pattern, then you would not come up with similar designs. Moreover, this type of tire pattern tends to have bigger tread blocks on the outer part of the compound. This is so that the tires stay stable while cornering. On the other hand, the inner tire section has blocks that are smaller and they also have water-channeling grooves, which function as heat dispersion from the rubber compound.
3. Unidirectional
In short, this tread pattern allows you to accelerate better due to less rolling resistance. Some may also require a shorter distance when stopping, making it ideal for performance cars that need quick acceleration and short stopping distance.
Can You Install A Different Tire Size On Your Car
Your car manufacturer states exactly what tire size is suited for your vehicle. These markings make it easy for consumers like you to find the right one and prevent making a wrong purchase. Some people are, however, interested in converting to a different size. This is not specifically what your carmaker suggests, but if you follow very stringent criteria, it may be possible. Without following these, you will suffer the consequences like voiding the warranty and other risks.
The key is to stick as close to your original tires diameter as possible. This is the most important thing, because various factors, like the gear settings, brakes, torque, speedometer, and tractor control are based on the diameter, which dictates how far the tire has to travel to get a full rotation. If the time or the length it takes for a full revolution is affected, your speedometer might show inaccurate readings, and your gears will also be affected.
This is the reason why the overall diameter should always be as close to the tire that your car was designed to run with. Unfortunately, it is not as easy to compute the outside diameter because tire sizes only include the inside diameter measurements. There are, however, online tire size calculators that help you compute whether the tires have similar overall diameters. The rule is, if you want to change your tire size, they should not have a difference in diameter of more than 1%, ideally, it should be less than that.
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Reading A Tire Sidewall
On the tire sidewall, youll find a list of letters and numbers. These indicate the size, type and performance of the tire.
- Youll usually find the letter P at the beginning. This means the tire is for a passenger vehicle, which is usually what the average person is driving. However, you could also see LT, which means the tire is for a light truck.
- Next, youll find three numbers, indicating tire width. The width is measured in millimeters from sidewall to sidewall. So, if your tire starts off as P215, it means the passenger tire is 215 millimeters in width.
- After the width, youll see a /, followed by two more digits. This is the aspect ratio, or the ratio of the tires cross-section height to its width. If the number were 65, then the height would be equal to 65% of the tires width. The bigger the aspect ratio, the bigger the tire sidewall would be.
- After the aspect ratio, youll find the letter R. This stands for Radial, or the layers that run diagonally across a tire.
- Right after that are two more numbers, which indicate wheel diameter. This is the size of the wheel measured from one end to another. It basically tells you the size of the wheel that the tire is intended to fit. So, if the sidewall says 15, then the tire is made for a wheel with a 15-inch diameter.
How To Determine The Perfect Tire Size For Your Car
The use of a three-number code assigns tires sizes. For example, for tire size series 255/55/16, the aspect ratio is 55, 2555 is the breadth, while 16 is the inner diameter size.
The external width of the wheel gets calculated by the length between the ends of each sidewall. To find the inner diameter, the aspect ratio of the wheel, and the rim size, remove an inch from the external width.
Multiply the aspect ratio of the wheel by two to find the external width, including the top and bottom sidewalls, and add it to the inside diameter. Then convert to inches from millimeters, this would give you 25.7inches as the measured height.
When you get the external width of the old wheel, cross-reference it with the replacement width, which is how to find out;what is the right tire size for your car.
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When Changing Your Tire Size Might Be Acceptable
It’s possible to change the size of your tires without actually changing the diameter. One example is if you want larger rims – you can buy tires that compensate for the larger rims by reducing the “height” of the outer tire. This is why the tires of cars with large rims have a much thinner “band” of rubber along the outside of the tire.
Other times you might want to change the size of your tires is when the factory-recommended size is rare and you want to find a more affordable option. Generally, you don’t want to go with tires that have a diameter that is more than 3% different from the factory tires. It’s also a good idea to consult with a trusted mechanic before switching to larger or smaller tires.
When Do We Replace Tires
Tire experts are often bombarded with questions like, when is the best time to replace my car tires? or what tires fit my rim?
Car and truck wheels are often replaced when their lifespan expires and also when the treads wear out from regular use.;;There are a few factors which can affect the lifespan of a tire.
- Pinholes
- Whether or not the driver is aggressive or careless
More often, car tire experts recommend the replacement of the tires when the driver or owner no longer feels safe while driving. This, however, is very subjective and more experienced drivers may get to notice this compared to new and first-time drivers.
If you are in this situation and are quite unsure whether you should change your wheels or not, check if your tires are still providing a level of traction that feels safe. How to do this? Simply check if its spinning or slipping. If yes, then that would automatically mean you have to replace them.
Another instance to replace tires is when they are already damaged. Look for cracks or bubbles. If you find any of these, then go to the nearest tire distributor.
Also, check the treads by checking the tread depth indicator. If they show damaged tread, then clearly, you have to replace your wheels. As a general rule, tires get worn when the tread reaches 2/32 inches. This means the cars ability to create traction on roads under normal conditions is very low.
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Selecting The Right Tires
Pick-ups and sport utility vehicles are usually engineered to handle up to a 15% oversize tire. Most tire dimensions can be calculated. For more information review the Tire Tech article, “Calculating Tire Dimensions.” While at first a 3% diameter increase or reduction in tire diameter may
Tyre Plus Sizing Calculator
In order to get the list of optional tyres, that are adequate for your new wheels, in the plus sizing calculator below, select your original equipment tyre size, the new wheel/rim diameter size and click on “Show Optional Tyres for the New Wheel” – the orange button.
NEW feature: Or, You can display adequate tyres for all three Plus Sizing methods: Plus One, Two and Three; at the same time, by clicking on the “Show Plus One, Two ‘n Three Tyre Sizes” – the blue button.
The calculator lists optional/alternate tyre sizes, based on the entered OE tyre size, where the overall tyre diameter difference between an optional tyre and the original equipment tyre fits within the range of -3% to +4% of the difference between the OE overall tyre diameter and the OE wheel diameter .
This formula is used by the leading tyre manufacturers.
Plus Sizing Calculator
Table columns headings:
- Column “Diff” may have percentages in the range from -3% to +4%, which are allowed. Its value represents the ratio of the difference between OT and OE tyre diameter and the difference between OE tyre and OE wheel diameter, presented as percentage. In other words, it says what is acceptable deviation of the OT tyre diameter from the OE tyre diameter.
- Column “Winter tyres only” that has an asterisk in a table row, means that the row tyre size is acceptable only for winter tyres.
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