Any self-respecting car enthusiast knows just how important wheels are. They decide grip, cornering ability, brake performance and how fast the car gets to highway speeds. While the stock wheels may be adequate in most cases, they don’t do the engine justice. Aftermarket variants are designed specifically with performance in mind and are the ultimate fun factor when you’re looking for a bit more push and shove.
Why Change Your Stock Wheels?
Aftermarket variants offer a bit more than what you currently have. Contrary to what most people think, you don’t have to spend an arm and a leg to get wheels that are better made, deliver better drivability and handling and ultimately look way better. And if you’re worried about scuffs or tyres deflating on their own, wheels that better handle day-to-day road use or a few fast laps around a track. Here’s where they score points compared to factory types:
- Improved handling – being lighter and stronger, any aftermarket car wheel is better attuned to the high forces acting on it in turns, corners and at higher speeds. This means a more stable car.
- Faster acceleration -with less sprung weight (below the suspension), the car gets to speed faster.
- Better braking – wheel makers put a lot of thought into designs that deal with heat generated when braking from higher speeds. Airflow is redirected toward brake parts, and cooler brakes mean shorter braking distances and ultimately, improved safety
- Durability – Have a factory car wheel curbed or bent from pot-holed roads? The added strength in aftermarket options, with improved production processes, means wheels that last longer in all driving conditions.
- Looks to die for – the choice of alloys and trace materials, as well as coating to prevent rust and surface damage, means wheels that look good even when abused. Buyers also get a multitude of designs to suit.
Choice of Materials
Designs and how the wheels look may be the first thing you think of. But your choice of materials also impacts whether they tick all the boxes. Aluminium alloys are by far the most popular choice, owing to their decent strength, corrosion and heat resistance, and machinability for different designs. They’re also more affordable than race-spec magnesium types. These are even lighter and stronger, and deal with heat much better so help with braking, but can be brittle, so will show damage faster on less-than-perfect roads. If you’re looking for wheels for the track, the mags are what to get. Both though are miles ahead of steel variants that come standard on lower-spec cars.
Differences Between Cast, Flow-formed and Forged Wheels
Besides materials, how each car wheel is made goes a long way in how it performs. Casting involves pouring molten metal into a mould and then machining it to get the result. This produces wheels of decent strength, but with more materials, those that are also heavier.
Flow-forming is similar, but here cast wheels are additionally spun around a mandrel while exerted to pressure and high temperatures. The process sheds a lot of weight without impacting strength. Flow-formed wheels are considered by many as the entry point for track use, with prices not much higher than their cast siblings. But if unrivalled performance, ultimate strength, and the lowest weight are priorities, then nothing beats forged wheels or monoblocs. These are made of a single piece of metal (hence the name) formed under immense pressure and heat, then rolling the wheel, and machining it to remove excess material. The extensive work and superior properties do have a price penalty, but you do get your money’s worth.
Sizing Wheels for Your Car
When considering any car upgrades, regardless of whether it’s wheels or exhaust systems, sizing and compatibility are key. In both cases, you’ll want something that fits. For car wheel sets, factors like diameters, bolt arrangement, and offset all affect handling. Diameters range from 13 to 22 inches, with most buyers choosing to upsize and then add lower-profile tyres. This helps with looks by negating empty spaces between the rubber and fenders. Bigger variants also are more attention-grabbing, especially when optioned in appealing spoke designs and colours.
Bolt arrangement, or PCD (pitch circle diameter) refers to the number of bolts in the rims and how far they are spread out. Most cars have a 4 or 5-bolt PCD, spaced evenly at 100, 110 or 120mm. This helps evenly distribute weight and secures the wheel to the hub.
Lastly, ET (German, “Einpress Tiefe), literally ‘insertion depth’ or offset refers to the distance between the mounting surface and the geometric centre of the wheel. Positive offset refers to types that have the mounting surface toward the front face of the wheel, a feature in most front-wheel drive cars, and negative offset with mounting surfaces toward the rear of the wheel, as found in many rear-wheel drive cars. This is stated in millimetres and engraved on the rim.
Before parting with your cash, consider styles, colours and coatings. You’ll want the wheels both to perform and look good while doing so. Choose from established brands, many of which have racing affiliations, and decide what falls within budget.