The Ultimate Wheels Buying Guide

1 Steel Wheels Versus Alloy Wheels

Choosing between the two-wheel types can be tricky. On the one hand, we have steel wheels that are wildly affordable but do not offer visual appeal or performance benefits. While on the other side there are alloy wheels that are extremely stylish and offer great performance results but cost a great deal more. Alloy wheels have many advantages over standard steel wheels, which is why they are widely used today, although, these advantages vary over the type of alloy wheel construction. Steel wheels are more utilitarian and often used on economy models where performance and aesthetics are not a priority. To choose between alloy and steel wheels, it is important to consider the wheel material along with its construction to obtain the right rims for your vehicle and need (click on the link to learn more about it). 

2 Things To Consider When Buying New Wheels

Changing your wheels for a set of new ones or switching from steel rims to alloys involves a lot of precise measurements and consideration. The following aspects will enable you to decide on the right set of wheels for your vehicle.

Wheel Size

There are two ways of choosing a wheel size. The simpler and more straightforward method is to go for the same size as stock wheels so you can use the same tires as well. This way you simply have to refer to your tire size and buy rims matching to original size. You can refer to this guide on how to read tire sidewall specifications. The second method involves taking various measurements to get the perfect fitment wheels and tires for your vehicle. If performing the measurements yourself, make sure to remove the tire from the wheel first as they need to be made with the tire uninstalled for accurate readings. You need to be familiar with the terms associated with wheels and various dimensions so that the wheel and tire fit correctly within the wheel well.

Wheel Diameter

The first thing to measure is the wheel diameter, which is measured across the face of the wheel, excluding the wheel lips (which are only used to hold the tire in place). Diameters for rims can vary from 10 inches all the way up to 30 inches. When choosing a larger wheel diameter it is important to understand that the tire sizes need to be altered to maintain the same overall diameter of the wheel and tire combined. This is done to maintain the factory’s overall diameter, which is the height of the wheel and tire combined. The speedometer, ABS, traction control, depends on this overall height to work properly. Deviating from the overall tire diameter by installing larger diameter wheels with the same size tires can cause these systems to malfunction and puts the vehicle and driver at risk.

Wheel Width

The width of the wheel determines the contact patch of the tire. An overly wide wheel can cause issues while mounting by contacting the fender, suspension, steering, or brake components. While an increased contact patch is good for handling, it can cause hydroplaning which can reduce vehicles’ ability to drive over wet roads along with reduced snow traction. When increasing the wheel diameter you also need to increase the width of the wheel and get appropriate tires for the width. The tire sidewalls bear the weight of the vehicle and mounting narrow tires on wider wheels below the safe tire width can cause the sidewalls to collapse.

Wheel Offset And Backspacing

The wheel offset is the distance from the hub mounting surface to the centerline of the width of the wheel. There are three types of wheel offsets: Negative, Positive, and Zero. Generally, cars come with zero or slightly negative offset wheels. A slight variation in the offset (≤1 inch) can increase handling characteristics, but major deviations can cause serious problems. It is important to choose the right wheel offset as it can alter suspension geometries and induce extra stress on various suspension, steering, and driveline components. Increasing the offset can also result in tire or wheel rubbing, which means the tire or wheel can contact the components found under the fender. To learn more about wheel offset and how to calculate it you can refer to our wheel offset article. Backspacing is the distance from the mounting hub to the back-end face of the wheel. Having too little backspace can hinder braking components to be mounted properly whereas increasing the backspace too much can cause similar issues to overly offset wheels.

Bolt Pattern

One of the most important things to consider is the bolt pattern. It is the number of studs or nuts the wheel has and the pattern or configuration it is arranged in. It is also referred to as PCD or Pitch Circle Diameter. Without the right bolt pattern, you cannot mount the wheel to your car, so matching the bolt pattern to your factory wheels is necessary. You can find the bolt pattern specification on the wheel or the vehicle owner’s manual. It usually comes as two numbers, for example, 5×160; where 5 is the number of bolts and 160 is the distance in mm between the center point of two bolts. You can find more information regarding the wheel bolt pattern and how to calculate it in this guide.

Hub-Centric

Factory rims are hub-centric, which means the wheel is precisely mounted on the hub. In a hub-centric connection, the weight of the vehicle is supported by the hub and wheel and not the lug nuts. The lug nuts merely secure the wheel to the hub mounting plate. Always choose wheels with a hub-centric connection as it eliminates the chance of lug nut shearing and the subsequent vibrations as well as safety hazards.

Lug Nut Style And Stud Length

The lug nuts and bolts are often overlooked, but they hold a lot of importance. Lug nuts come in different sizes and styles like hex, mag type hex, hex spherical seat, hex conical seat, etc. The lug stud length can also vary depending on the size of the wheel and hub plate. Choose the right type, size, and style of lug nut and bolt for your rims to ensure precise and sturdy mounting.

3 Plus Sizing

Increasing the size of the wheel diameter and wheel width is termed as Plus Sizing and decreasing wheel diameter is called Minus Sizing. Plus sizing the tire can increase your handling and steering responses and aid driving dynamics. The look of low-profile tires is extremely popular, as it can drastically up the visual appeal of any car. The lower-profile tires are paired with larger diameter wheels to complete the sporty look. 

There are a few rules to be followed when picking new wheel sizes to ensure the product fits in your vehicle. Plus sizing only works if you maintain the overall tire diameter to the factory-installed tires to ensure the various systems like ABS, traction control, speedometer, etc. work properly. This is because the overall tire diameter is used to calculate the rotational speed and increasing or decreasing the diameter can change the readings. The mechanical driveline gearing also depends on the overall tire diameter and any changes can induce more stress on the components leading to imminent failure so it is essential to maintain the original tire diameter.

To carry out plus sizing you must select O.E. equivalent tire diameters and load capacities and combine wider, lower-profile tires with wider, larger diameter wheels. This ensures the accuracy of the vehicle’s speed-dependent systems remains consistent while providing improved responsiveness, reduced braking distances, and increased stability.

The rule is that for every 1-inch increase in wheel diameter, the tire width is increased by 10 millimeters and the tire sidewall height is decreased by 5 to 10 percent. 

For example, if your original tire specification is 235/50R16 and you wish to upgrade to 17-inch alloys, you will have to choose a tire with specification – 245/45R17 or 245/40R17. It is a good idea to calculate the overall height of the original and the new tire and wheel package so that you buy the right tire size. To calculate the overall height of the tire and wheel assembly, you can refer to our tire size calculator article. You can also learn more about how to read tire sidewall specifications here.

Increasing one inch in wheel diameter is called “Plus One”. ”Plus Two” and “Plus Three” are also common upgrades, especially on modern vehicles. The same rule must be followed for “Plus Two” and “Plus Three” fitments by simply multiplying the variables by 2 or 3.

There may be a small difference in the overall diameter by order of +/- a few tenths of an inch. But these small variations are negligible and do not affect the system. The results are a negligible +/- four-tenths of an mph speedometer variance.

Minus sizing is done on off-road and heavy-duty tires to gain larger rubber sidewall height and reduce the wheel diameter. This is especially useful in off-road vehicles where the larger rubber compound helps absorb the uneven terrain and prevents wheel damage. Minus sizing is also commonly done on winter tires which are usually spare tires only used in the winter months.

4 How To Find The Right Alloy Wheels For Your Car? How Do I Choose Alloy Wheels For My Car?

There are two ways you can go about finding tires for your specific vehicle:

A. By Size

B. By Vehicle

A. By Size

If you have a specific size in mind, then finding the right tire and wheel combo will not be hard. Simply load in the specification and order it. This method is however more complicated since you need to be sure of the size of the wheel and tire, ensuring all the factors, as discussed earlier, are within specifications. Even a slight variation can cause trouble in fitment, so be sure you make a wise and informed decision.

B. By Vehicle

This method is more common since you can find predefined wheels and tire combos specific to your vehicle’s make and model, which makes the ordering process easier and trouble-free. Although this entirely depends on your make and model along with its popularity and availability. Thankfully at Partsavatar, we stock a large range of make and models across an array of years so you can find the right wheels and tires for your car – hassle-free.

5 FAQs

Q) Can I Put Wider Tires On My Stock Rims?

It is possible to add wider tires on stock rims or wheels. You can add (or even reduce) a maximum of 20 mm to the tire width for any given wheel. The manufacturer usually installs the “ideal tire width” for the given rim. You can refer to the tire width chart below to get an idea of how wide tires you can fit on your rims. For example, for an 8-inch wide rim or wheel, there are three possible tire widths you can fit – 215 mm, 225 mm, 235 mm, and 245 mm. 215 mm is the minimum safe tire width. 225 or 235 mm is the ideal tire width and 245 is the maximum tire width you can install on an 8-inch rim.

Tire Width Chart 

Q) How Do You Know What Size Tire To Get For Your Rims?

There are three measurements necessary for any tire – tire section width, tire sidewall height, and wheel diameter. The tire section width can be determined using the wheel width and referring to the tire width chart. To get the right tire sidewall height ratio, you need to keep in mind the original tire diameter and calculate the overall height of the tire and wheel assembly accordingly. Refer to the tire size calculator to learn how to calculate the overall tire diameter.

Q) What Offset Rim Do I Need?

It is usually recommended to stick to the OE wheel offset spec which can be found engraved on the tire after the letter ‘ET’. To find the right wheel offset for your wheel, you need to refer to the wheel offset chart available in our wheel offset guide.

Q) Do I Have To Get New Tires With New Rims?

If you have upsized your wheels to a larger diameter then you will have to change the tires to match the wheel diameter. If you have only increased rim width then you need to make sure the tire width falls within the recommended tire width settings. For example, if you had an 8-inch wheel on a 235/40R17 and swapped them for wider 9-inch wheels then you can still fit the tire on the same wheel as it meets the minimum tire width for the wheel (according to the tire width chart). However, if you had a 225/45R17 tire then you will need to get wider tires to match the wider wheels.

Q) How To Find Your Vehicles Bolt Pattern?

For wheels with 4, 6, and 8 bolts finding the bolt pattern number is simple. Just measure the distance between the center of two opposite holes. For 5 and 7 lugs, the measurement is not that simple. To get an estimate you can measure from the center of one lug to the outer edge of the lug that is farthest away. Alternatively, you can find the correct bolt pattern in your owner’s manual.