How Do I Know What Rims Will Fit?

Rims are not cheap, and getting a mismatched set is not an option. It does not matter if you are looking for a set of custom rims to boost the performance or looks of your vehicle or want to swap wheels with another car. Achieving a perfect fit is the most important thing here.

If you want to know what rims will fit your vehicle, you need to know the exact specifications. There are four key elements you need to find out before searching for new wheels. All this information can typically be found inside the owner’s manual.

Key Takeaways:

• Four critical elements determine whether a rim will fit your vehicle: bolt pattern, backspacing, offset, and center bore.
• Proper rim fitment is crucial, not just for aesthetics but for vehicle safety and performance.
• Not all rims fit all cars or all tire sizes. Specific measurements, like bolt pattern and rim width, determine compatibility.
• Installing the wrong rims can lead to numerous issues, including inaccurate odometer readings, tire damage, altered handling, and potential suspension failures.

Your manual usually can provide all the information you need to pick rims with the same measurements as your OEM wheels. However, that is not always the case. If you buy a used car, it might actually already have custom wheels with different specifications.

In that case, you need to learn how to measure the exact rim size yourself. Luckily for you, we have a simple guide to determining what rims will fit your vehicle like a glove.

4 Key Elements of Wheel Fitment

If you want new rims to fit the vehicle, you need to do some work and figure out the most important parameters. For a perfect fit, the bolt pattern, backspacing, offset, and center bore. Matching these parameters will ensure that your new rims will sit securely where they belong and never cause an issue.

And in contrast, if you mess up this step, there will be consequences. If the rims are too small to fit the vehicle, you will have to get a new set, and that’s it. But if they are too large, the rims will not hold onto the hub and cause vibration, wobbling and all sorts of problems.

Bolt Pattern

Every vehicle model has a specific bolt or lug pattern determined by engineers to support and distribute the weight better. Bolt patterns vary in size and number of bolts per wheel. They can be even-numbered or odd-numbered.

Compact vehicles usually sport 4-lug or 5-lug rims, while larger vehicles like SUVs and pick-up trucks can have up to 8 lugs per rim. Heavier vehicles or models designed for difficult tasks usually have more lug nuts in a pattern to distribute the weight properly and prevent damage.

Obviously, to make sure your rims fit the hub perfectly, you need to match the exact bolt pattern. The number of holes for lug bolts and the spacing between each of them on the rims must correspond with the same pattern on the wheel hub. To do that, you need to learn how to measure your bolt pattern.

The simplest way is to look up the stock wheels’ bolt pattern in the owner’s manual. But that doesn’t always work, especially if you have bought a used vehicle that could have been modified. Custom wheels can differ in size from what is advertised. So you should know how to measure the bolt pattern.

Measuring even-numbered bolt patterns (4, 6 and 8-lug rims) is very simple. Just grab a bolt pattern gauge or a measuring tape and measure from the center of one hole to the center of the hole directly across from it. This method, however, will not work for 5-lug patterns.

Usually, this measurement is presented in millimeters. And for 4-lug rims with the distance between lug bolts equal to 100mm, it looks like this:

4x100, where 4 refers to the number of bolts in the pattern with 100mm between opposing holes. Some manufacturers use inches, and in that case, the numbers will look like this 4x3.93 for the same rims.

5-bolt patterns can be a bit trickier because it is impossible to find a hole directly across from another one. They all form a star shape. So what you need to do is measure from the center of your starting hole to the backside of the second hole away from it.

Always make sure you get the measurements right. Double-check to save yourself from headaches and needless expenses. Once you do that, you are good to go and search for the rims that will definitely fit your vehicle.

Wheel Backspacing

Another vital measurement that ensures the rims for the car is backspacing. It defines how much space there is between the mounting pad and the inner edge or backside of the wheel. It is meant to help you leave enough space for the wheel to not rub against other parts, like suspension, for example.

If you have too much backspacing for your wheel, it might interfere with the inner suspension or brake components and do a lot of damage. On the other hand, too little clearance can cause the wheel to protrude outward more than desired and rub against fender flairs. Both are equally devastating for the wheel itself.

To measure how much backspacing you need, use a straight edge (like a ruler or a spare piece of wood) and a measuring tape. Place the straight edge across the back of the wheel (from one side to the other), and measure the distance from the hub mounting surface to the straight edge.

Compare the measurements to the specifications in your owner’s manual to tell if you have the right amount of backspacing.

Wheel Offset

Backspacing and offset often go hand-in-hand with rim specifications. But unlike backspacing, wheel offset describes the distance from the hub mounting surface to the centerline of the wheel. And it can be positive, negative, or zero:

• when the hub mounting surface is towards the outside, it is a positive offset.
• when the hub is closer to the inside of the wheel, it is a negative offset.
• and the offset is zero when the hub mounting surface is even with the centerline of the wheel.

Knowing the offset of the rims is important because this specification, among other things, affects how the vehicle handles. If you pick rims with the wrong offset it can seriously impair steering performance or even damage suspension.

To measure your wheel’s offset, subtract the wheel backspacing from half of the overall wheel width. If the resulting number is positive, you have a positive offset. If it's negative, you have a negative offset. And zero is self-explanatory.

For example, your wheel width is 8 inches and backspacing is 10 inches.

Half of the wheel width = 8 inches ÷ 2 = 4 inches

Subtract backspacing from half of the wheel width = 4 inches - 5 inches = -1 inch

The result is negative. Hence, the wheel offset on your rims is negative too. You do not need to match the offset exactly. If you stay within a 5-millimeter range, you should be just fine.

Center Bore

The Center bore is the hole in the center of the rim that must perfectly align with the hub of the vehicle. Otherwise, the wheel will not be secured. It is easy to measure using a caliper or a ruler.

Without a perfect fit between a rim’s center bore and the wheel hub, there will be issues. Any gaps, no matter how small, will cause vibration and wobbling. This will eventually start destroying the wheel.

Changing rims is not a daunting task, but you still have to pay attention to these four important factors. They will determine if the rims fit the car. So, take your time and check them one by one.

Plus Sizing or Up Sizing During Rim Fitment

Finding a perfect replacement for your rims is one thing. But if you want to bring it one step further and upsize or downsize with new rims, there will be other things to keep in mind. It can be slightly more complicated, but aren’t custom wheels worth some extra effort?

Larger rims can give a vehicle better handling and a more aggressive look. But your main concern should be safety. If the rims don’t fit, this is not plus sizing. It’s a poor decision.

Basically, plus sizing means choosing rims with a larger diameter while decreasing the tire's profile (sidewall height), ensuring that the new tire remains roughly the same overall diameter as the old one. This helps you keep vaguely the same wheel diameter to not throw the odometer and speedometer far off.

Compensating the larger rim size with smaller tires will help with another up-sizing issue. If you don’t balance out the wider radius, the tire can come in contact with the vehicle parts like suspension or fenders. This is never a good thing to happen and can result in disaster on the road.

How Do You Measure Rim Size?

The rim size is represented by its diameter and width. You need only two measurements to know the exact size, but there are more specifications that you should still consider, like offset, backspacing, etc.

The diameter of the rim is the distance across the wheel from one side to the other. It is usually measured in inches. The most common diameter you will see in regular small cars is from 14 to 21. Luxurious or fast cars tend to have wheels of bigger diameter.

Width is measured across the barrel of the wheel, from the back of the mounting pad to the back of the bead seat. And it is also measured in inches.

How Do I Know What Rims Will Fit My Tires?

To fit tires onto the rims, you need to know two important measurements: the diameter and width of the rims. Luckily, the tire size is stamped on the sidewall of the tire itself. For example, a size like "215/60R16" indicates the tire is designed to fit on a 16-inch diameter wheel.

The width should also match perfectly to ensure proper fit. The tire manufacturer will usually provide a range of widths that are suitable for a particular tire.

And don’t forget that you should not upsize while the tire sidewall remains the same. It can cause unnecessary problems with fitment.

Can Any Rim Fit On Any Car?

The short answer is no. Some rims will fit a range of car models with similar wheels, but that’s it. Factors like bolt pattern, center bore, offset, diameter, and width of the rim determine whether or not the rims would fit the car.

These specifications differ more often than not from one vehicle to another. That is why there is no such thing as universal rims that could fit any car.

Do Rims Have To Be The Exact Size To Fit?

In most cases, yes. The number of lug nuts, space in between them, rim size and other specifications should match for the rim to fit the vehicle. But there are ways to make that happen, even if the rims are too large or have a different bolt pattern.

Wheel adapters can work wonders with bolt patterns, for example. Some safety concerns are associated with them, and adjusting for a mismatched set of rims can be expensive and unproductive. But if you believe it is worth a shot, go ahead.

There are ways to make larger rims fit. But if the rims are too small, don’t even bother. In my experience, that never yields any decent results.

Do Rims Fit All Tire Sizes?

Unfortunately, no. Every rim size is designed to fit specific tire sizes. For example, a 17-inch rim is designed to fit tires that have a 17-inch diameter.

And do not forget about the width. The width of the rim also influences your choice of tire width. That narrows down your options a lot but that is not always a bad thing.

Do All 5-Lug Rims Fit The Same?

Of course, not all 5-lug pattern rims are the same because they can vary in space between each lug bolt. For instance, a 5x114.3mm bolt pattern is different from a 5x100mm pattern, and they are not interchangeable.

So, even if the rims have the same number of bolts, measure the distance to make sure the rims can fit.

What Happens If You Put The Wrong Rims On Your Car?

Do not try to install rims that do not fit your car. Using the wrong rims can lead to a range of issues, including tires rubbing against the fender or suspension, which causes serious damage. It can also alter vehicle suspension geometry, resulting in poor handling, potential braking problems, wheel detachment, or uneven tire wear.

A mismatch in rim and tire diameter can result in inaccurate speedometer and odometer readings. And moreover, incorrect fitment can strain suspension components, prompting wear or causing failure.