The Ultimate Guide to Car Alloy Wheel Modifications
Posted on: 01/03/2024We’ve said it before and we’ll say it again: wheels can make or break a car. With the right wheels - and tidy fitment - any car can be completely and utterly transformed. Choosing the right wheels and making them fit properly isn’t always as easy as it sounds, though. There’s plenty to consider, and a whole lot of confusing terminology to get your head around.
That’s why we’ve decided to put together a comprehensive guide that covers everything you need to know about alloy wheel modifications (and nothing you don’t). If you want to make your car look the part and improve its performance, read on to learn how to find the right set of performance wheels and tyres for your car.
Below, we’ll explain all of the key terminology you need to know, round up the benefits of swapping out your wheels, and run through other upgrades and accessories you might want to invest in to make your new wheels really pop. Let’s get started.
Why upgrade your wheels? A look at the benefits
Before we run through the process of choosing new wheels, let’s first recap the benefits of ditching the stock ones. Hint: there’s more to wheels than just the way they look.
Reduced weight: Unless you drive something that’s been built from the outset for track use, your car’s stock wheels likely leave room for improvement in terms of weight. Switching to lighter aftermarket items will reduce unsprung weight, improving your car’s handling and performance capabilities.
Fit wider tyres: Want more grip? If you upgrade your wheels to wider aftermarket ones, you’ll be able to fit wider tyres to pull more lateral g-force in the bends.
Fit bigger brakes: Upgrading to larger alloys will give you additional clearance, allowing you to fit bigger brakes. Many aftermarket rims have thinner spokes than stock ones too, allowing more air to reach your brakes to keep them cool.
Adding value: If you do it right, upgrading your wheels could add value to your car, or at least make it easier to sell. This applies particularly to cars that originally came with steel wheels; fitting alloys will help set your car apart from the rest, attracting more buyers.
Finding alloy wheels that fit your car
When you’re shopping for new alloys, there’s more to think about than just the way they look: you need to make sure they actually fit your car. If you don’t pay attention to the diameter, width, offset and PCD of your new wheels, you’ll be disappointed with the end result… and they may not even fit your car at all. Let’s take a look at the key parameters that affect how a wheel fits.
Diameter
Given in inches, diameter refers to the size of the wheel rim (or face). Depending on your needs and preferences, you might want to opt for wheels that are smaller or larger in diameter than the stock equivalents. If you go for smaller wheels, make sure they’ll clear your brakes first - and if you choose larger wheels, check that there’s room in your wheel arches to accommodate them.
Width
The width of the wheel barrel, again given in inches. You may also see the width of a wheel described as being ‘8J’ instead of 8 inches. Typically, if you’re upgrading your alloys you’ll opt for wider-than-stock wheels, allowing you to fit wider, gripper tyres. Wider wheels also tend to have a more dished or concave face, giving them a more aggressive look.
Offset
Measured in millimetres, wheel offset refers to the distance between the mounting face of the wheel (where it bolts onto the hub) and the true centreline (the middle of the wheel’s barrel). The lower the offset, the more the wheel will poke out of the arch. In extreme cases, the offset can go below zero, resulting in a negative offset figure. To give you an example, a wheel with an offset of +20 would stick out 20mm further than an equivalently-sized wheel with an offset of +40. Meanwhile, a wheel with a -40 offset would stick out 20mm further than one with an offset of -20.
PCD
PCD (pitch circle diameter) refers to a wheel’s bolt pattern - in other words, the location of the holes used to mount it to the hub. Like offset, PCD is measured in millimetres. A typical PCD would be 5x100, meaning that the wheel has five holes which are 100mm away from each other.
Centre bore
Centre bore, given in millimetres, refers to the size of the hole in the mounting surface of the wheel. This hole is used to securely centre the wheel on the hub, so it must be equivalent in size (or larger) than the hub’s mounting surface in order for the wheel to fit. For example, if your chosen wheel has a centre bore of 65mm but your hub’s central mounting surface is 75mm in diameter, the wheel won’t fit.
Other considerations to bear in mind
Now you know how to find wheels that physically fit your car, let’s move onto some secondary considerations.
Colour and finish
Most wheels come in a painted or powdercoated finish, which is hard-wearing and pretty simple to repair. If you’re looking for something a little different, you might want to consider polished, chromed, anodized or diamond cut wheels instead - but these finishes have their downsides. They tend to require more in the way of maintenance and can be more expensive and time-consuming to repair, so you’ll need to take good care of them if you want them to look pristine for years to come.
Then there’s colour. Painted, powdercoated and anodized wheels come in a vast array of different hues, from subtle greys, silvers and blacks to look-at-me reds and golds. From stealthy shades to vibrant, stand-out colours, you won’t be short of options.
Brand
There are tonnes of different wheel brands out there, some of which are more revered than others. The likes of HRE and Rotiform wheels are particularly desirable, so you’ll have to pay a premium to get your hands on them - but you’ll be rewarded with high-quality wheels that last. They’ll hold their value well, too.
Despite all of that, there’s still a lot to be said for popular entry-level brands like Bola and Wolfrace. If you’re on a budget and want to give your car a makeover, these brands give you the chance to bring your vision to life without breaking the bank.
Construction
Single-piece, two-piece, three-piece… cast, flow formed, forged… there are so many different wheel designs out there, each with their own set of pros and cons. Most budget wheels tend to be cast, single-piece items, while three-piece and forged wheels sit at the opposite end of the price spectrum.
Which is best ultimately depends on your budget and requirements. Forged wheels are stronger and usually lighter than their cast counterparts, but unless you’re a professional racing driver, you’re unlikely to notice a difference from behind the wheel.
Supplier
As you’ve probably gathered by this point, choosing wheels for your car isn’t a particularly straightforward process - especially if you’ve not done it before. That’s why you should pick your supplier carefully. Choosing a company with in-depth wheel fitment knowledge will save you an immense amount of hassle and legwork; let them answer your technical questions and solve your dilemmas while you focus on choosing wheels you like the look of. At LK Performance, we can even install your new wheels for you, making the process as simple as can be.
What accessories will I need?
Depending on your car and the wheels you end up choosing, there are a handful of different accessories you might want or need. Let’s run through each of the most popular wheel fitting accessories and take a closer look at what they do.
Wheel nuts or bolts
The most self-explanatory of the bunch! Wheel nuts or bolts secure your wheels to the hub, making them a vital component to get right. Most standard wheels use nuts or bolts with a 90-degree taper, while many aftermarket wheels require bolts or nuts with a 60-degree taper. Before you fit your new wheels, make sure you’ve got the right bolts or nuts to hand.
Spigot rings
Remember what we said earlier about centre bore? If the centre bore of your new wheels is larger than the mounting surface on your hub, you’ll need spigot rings. These plastic or aluminium devices slot inside the hole on the back of the wheel, adapting the centre bore to perfectly match the mounting surface on your wheel hub. Spigot rings help eradicate wheel wobble and ensure that your wheels are securely and centrally fitted, making them a must-have.
New tyres
If you opt for larger diameter or wider wheels, you’ll need larger tyres to match. Now’s the perfect time to switch to more capable performance tyres, improving your car’s straight-line traction, cornering performance and stopping power.
If your new wheels poke out significantly further than the stock ones, make sure you take this into account when choosing your new tyres. Beefy performance tyres might sound good on paper, but if they foul the arches you’ll soon regret your decision.
Wheel spacers
If you choose wheels with too high of an offset or too narrow a width, you can add wheel spacers later on to push the wheels out further, giving your car a more aggressive look. By increasing the track width, spacers can give your car more sure-footed, stable handling too.
There are a variety of other situations where spacers are required. For example, if you’ve switched to wider wheels that foul on your suspension arms or brake callipers, you may need a spacer to add a little extra clearance.
Although spacers have their benefits, it’s always preferable to choose wheels that fit correctly from the get-go. Spacers are perfectly safe when installed correctly, provided you choose the right type of spacer. Always opt for quality hubcentric items and, if you need bolt-on spacers, always make sure they’re torqued down correctly.
Suspension modifications
Although wheels can have a transformative effect on the look of a car, the best-looking modified cars will always combine aftermarket alloys with upgraded suspension. The two go hand-in-hand, allowing you to lower your car’s ride height and dial in the wheel fitment to your liking with millimetric precision.
The go-to suspension upgrade for most builds is a set of coilovers. Coilovers allow you to not only adjust the ride height of your car but, in many cases, fine tune the behaviour of the dampers to suit your driving style. Depending on the coilover brand and the car you drive, they often include camber-adjustable top mounts too.
Alternatively, you could go for an air ride kit. Air ride gives you total flexibility: you can slam your car to the ground whenever you want or raise it up, making traversing speed bumps a doddle. Coilovers tend to be more well-suited to performance driving, while air ride remains a popular choice for show cars and daily drivers. Both have their merits - which is best depends entirely on your point of view.
Find the right wheels and tyres for your car today
Need advice to find the right wheels, tyres and accessories for your build? Speak to the experts at LK Performance today. Not only do we stock a vast range of wheels, tyres and accessories, we make it easy to find parts that suit your car: you can even browse our range by car make and model.
If you need further advice or have any questions at all, reach out to our friendly team today. From recommending wheel and tyre combinations to advising on the need for spigot rings, aftermarket bolts and other accessories, we’re here to help with all your wheel and tyre needs.