FAQ: Wheel Fitment and Offset Information

[KevinD]

Base Model Wheel and Offset Information

Bolt Pattern: 5 x 114.3

Front
Wheel Size: 18" x 7.5"
Wheel Offset: +35

Rear:
Wheel Size: 18" x 8"
Wheel Offset: +35

Tire Information
Brand: Bridgestone Potenza RE-92A 91V UTOG 260 A A

Size
Front: 225/45/VR-18
Rear: 245/45/VR-18

Track Model Wheel and Offset Information

Bolt Pattern: 5 x 114.3

Front:
Wheel Size: 19" x 8"
Wheel Offset: +35

Rear
Wheel Size: 19" x 8.5"
Wheel Offset: +35

Brand: Bridgestone Potenza RE050A 89Y UTOG 140 AA

Size
Front: 225/40/VR-19
Rear: 245/40/VR-19

For more information regarding custom wheel sizes and how to size up those wheels, please see The Offset Thread.

Note: The following is lifted from Unabomber's very good FAQ on wheels from NASIOC.

Which manufacturer is best? This topic is highly debated. There are just too many factors to consider. The main category breakdowns are:
a. Price
b. Looks
c. Wheel weight savings over current wheel weight.

What wheel material is best? Most wheel manufacturers use various proprietary alloy compositions. There is no irrefutable evidence that one alloy is better than the other.

Which wheel construction method is best?
There is no irrefutable evidence that one design is better than the other. This website has an excellent description of the different wheel construction methods.

What is wheel offset? The offset of a wheel is the distance from its hub mounting surface to the centerline of the wheel.

Why is wheel offset important? Wheels using improper offsets can cause damage or accelerated wear on suspension components or body panels.
The stock offsets are listed above. If your wheel width and offset is within this range or close (+/- 2mm), your wheels have the proper offset.

Special consideration must be payed for those with the Track Brake Package. The Brembo calipers are significantly larger then the Base Model. For Track Model owners, the minimum offset for the front is +35. Any higher (> 35, ie, +38) will not work without spacers or other products.

Just because it fits does not mean it is right

Are there any downsides to wheels? There have not been significant amounts of problems with wheels. Heavier weight wheels, through rotation mass can multiply their weight which will result in decreased performance. For example, an additional 5 lbs per corner of wheel weight (20 lbs total) has an equivalent effect on acceleration of 50-80lbs of weight in the car. Also, as you increase wheel size, realize that you are increasing the wheel's distance from the center of rotation. Due to wheels having rotational mass, larger wheels have a larger rotational mass. For example, spinning a 1lb weight 8 inches from the center of a wheel requires less work than spinning that same weight 9 inches from the center. Unsprung weight: "Unsprung weight is the total weight of components not supported by the springs. This includes control arms, brake components, spindles, wheels and tires. Reducing unsprung weight is a key factor to improving a vehicle's handling." Among other things, it allows the suspension to react faster and improves the tires' contact with the road, producing more grip on rougher road surfaces. The easiest way to reduce unsprung weight without otherwise compromising performance is to reduce the combined wheel/tire weight. See this webpage for more details on unsprung weight.

How can I be sure my new wheels will fit?
You have a few options to ensure proper fitment prior to purchasing. Ask the wheel retailer and ensure you are aware of their return policies. Ask fellow owners in the Technical Section. Get a general idea via the calculator found on this website.

Will I need new lug nuts?
This is a question to ask the retailer. It can also be an additional expense to keep in mind during the time of purchase. There are three different types of lug nuts with the main difference being the seating surface shape of the lug nut to the wheel. Remember: always keep a set of OEM lug nuts around for use with the spare, if using another type of lug nut.

Where do I buy wheels? Every Hyundai/Import performance store sells wheels. For purchasing, support your local economy or the NAHGOC Vendors.

If I change wheel size, will it effect my speedometer? No, however, if you change the tire circumference, there will a speedometer variation. This website contains a nifty calculator that will assist you determining your new speedometer tolerances as does this website.

How important is wheel balancing? Very. Wheel balancing is a procedure that improves tire performance by ensuring that the weight of the wheel is evenly distributed. Conversely, an out of balance wheel can accelerate tire and/or suspension component wear. Traditional tire balancing methods are cheap and effective methods to prevent the downsides of an out of balance wheel.

What is radial force balancing? Advanced users, and those with wheel/tire vibrations not solved by normal balancing, might consider the additional cost of radial force balancing. Traditional balancing uses weights to offset minor variations in the weight of the wheel/tire combination around its circumference. In actual use, though, the wheel/tire combination is pressed against the road surface, and so variations in the "springiness" (or radial force) of the tire around its circumference can also cause problems. This radial force variation (RFV) does not necessarily have any connection to "high" or "low" spots in the tire/wheel, and so it cannot be corrected just by measuring runout on an unloaded wheel. The wheel/tire combination needs to be loaded (usually done by pressing a spinning cylinder against the wheel/tire combo, as in a dyno) to measure RFV and calculate weight placement to counteract it. See here for more details. This method is more expensive and runs around $20 per tire depending on your locale. Radial force balancer locator.

What about wheel weight placement? Advanced wheel balancing machines have the technology to let the technician know the optimal placement of wheel weights. This can be in the form of outside the rim, inside, or middle of the wheel "tape weights". Other than purely aesthetic reasons, it is always best to default to the judgment of technology vs. appearance. Always specify your wishes prior to wheel balancing. Some technicians assume the owner does not want externally mounted wheel weights in the case of aftermarket wheels.

How hard is it to install wheels? Allow around one hour for install time. Professional installation, depending on your area, is around $75. This is one vehicle modification that is very simple and can be successfully accomplished by even the greenest shade tree mechanic.

How do I install wheels? Refer to the wheel manufacturer's instructions. For wheels without instructions, below is a link to one of the better known wheel installation instructions:
tirerack.com's instructions

[chrisssteeven]

Well,I've not heard about anything as serious as the wheels coming off when using spacers, but vibration can certainly be a real concern.You just have to realize it's just one more thing that needs to be installed / balanced perfectly on the hub.One wheel / tire specialist I spoke to about this very issue told me the AR is particularly susceptible to vibration with spacers,but didn't elaborate beyond saying "just make sure you get a quality spacer if you go that route.Personally, after hearing about the issues other owners had to endure,I didn't want to risk it and found a wheel I liked that was a direct fit without spacers.

[KevinD]

Very true. I've seen folks have their wheel bearing life cut in half using a poorly installed spacer.