Detailed or additional information can be found on the tire manufacturer websites or at the Tire Rack (www.tirerack.com).
The Basics Of Wheels
Wheel lingo is simple. In searching for a set of aftermarket rims for an '06 Audi A3, we located a nice set of 19-inch Privat Netz. According to Privat's website, the wheel specifications necessary to fit the vehicle are:
8x19 with a 5/112mm bolt pattern and a +40 offset on all four corners.
* 8: Wheel width in inches.
* 19: Wheel diameter in inches.
* 5/112: Read it "five by one-twelve." The first number indicates the number of lug bolts and the second number is the bolt pattern distance in millimeters. For asymmetrical five-bolt patterns, the distance is measured from the back of one bolt hole to the center of the opposing bolt hole. For other symmetrical bolt patterns, it's the distance from the respective centers of opposing bolt holes.
* +40: The wheel offset, the distance from the front wheel hub mounting surface to the exact center of the wheel in millimeters. The symbol can be either positive (+), negative (-), or zero. In this example, + indicates a positive offset of 40 millimeters from the exact center of the wheel.
You can measure the offset by looking at the wheel cross section with the tire removed. As indicated above, there are three offset types. Zero offset occurs when the mounting pad is at the exact center of the wheel (rim to rim). Positive offset indicates when the mounting pad is closer to the face of the wheel. Negative offset indicates when the mounting pad is closer to the back of the wheel.
Proper offset is crucial to keep your tires from rubbing the insides of your wheel wells during cornering or under load.
A friend of mine bought a set of wheels with a +35 offset from eBay for his lowered 2007 GTI. He got them mounted up with a set 225/35R19 tires. At first glance things looked fine but after a few speed bumps and sharp corners, he realized there was something terribly wrong-he had ripped out his fender liner. What he really needed was an offset of +40 or +45. In that case the wheels would be sitting 5-10 millimeters further inward, giving the tires plenty of room to clear the fenders.
The Final Word
When it comes down to picking out a set of wheels and tires, it's always best to consult with an expert who has experience with your specific vehicle type. Also, having a clear concept of what you'll be using the wheel/tire combination for will help you find the proper set of tires.
Be cautious when you're looking at the various parameters-bolt pattern, diameter, width. And while these are all important, it's the wheel offset that will ultimately determine the success or failure of a rim and tire setup. Sometimes just a few millimeters can make all the difference between smooth sailing and scrubbing tread on every bump and corner.
The HRE M40 Monoblok is a classic motorsport design with a modern twist. Each wheel is manufactured from 100% forged 6061-T6 aluminum and tailored to each application, eliminating the need for adapters while retaining tire pressure monitoring systems (if equipped). Finite Element (FEM) analysis, a computer tool that allows HRE engineers to reduce weight and rotational inertia while maintaining strength and durability, is also employed.Applications: Aston Martin, Audi, Bentley, BMW, Ferrari, Lamborghini, Maserati, Mercedes-Benz, Porsche
The O.Z. Racing Alleggerita HLT is manufactured using High Light Technology (HLT), a process that uses rollers to compact the aluminum during the low-pressure casting process to help reduce weight and increase strength. The process reduces total wheel weight by a claimed 10 percent without sacrificing durability. Eight colors are available: anthracite, black, blue, gold, matte graphite, orange, red, and white.Applications vary
The European design team at Modulare Forged wheels is driven by individualization with a focus on style and performance. The Modulare M14 three-piece forged wheel was designed with three core values: aesthetics, low weight, and high quality. Each wheel is manufactured using 6061-T6 aerospace-grade aluminum, hand assembled, and available in a variety of custom finishes.Applications vary
To ensure each wheel meets the company's standards, Enkei created its own rigorous testing program known as SPEC-E. Program standards exceed Japan's JWL requirements, with higher drop points and a 20 percent cycle increase in the rotary bending and dynamic radial fatigue tests. The Enkei EKM3, pictured, is available in hyper silver or gunmetal finishes.Applications: Audi, BMW, VW
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