Alloy Wheels Explained
Generally speaking there are 2 main types of wheels on vehicles today - Alloy Wheels and Steel Wheels.
As the names suggest, Alloy Wheels are made primarily of Aluminium (Alloy) and Steel Wheels are made of Steel. Alloy Wheels are far more common nowadays and come on most vehicles as standard from the car manufacturer, but Steel Wheels can appear on base or lower trim models. Magnesium is also used but is expensive and mainly only seen in very lightweight track wheels.
Alloy Wheels fitted to a vehicle make a big visual difference, and the right wheels to compliment a vehicle can be a great upgrade. It increases the visual appeal of the vehicle but also it can have a very positive improvement to the driveability. We often compare Alloy Wheels to a pair of shoes, there are correct shoes for paricular occasions and there are many different styles to pick from - suiting all tastes.
The pros and cons of Alloy Wheels:
Improved visual appearance - larger wheels tend to visually fill the wheel arches better being more proportionate to the rest of the body. This can improve the desirability especially when selling the vehicle on.
Improved driveability – A reduction in unsprung weight offers advantages in more precise steering, acceleration improvement and a reduction in fuel consumption.
Improved grip – If you increase the width of the tyres then this will increase your surface area of the tyre in contact with the road. With smaller wheels the tyre profile is large causing flex of the tyre under the weight of the vehicle when cornering. Steering response is dampened and can cause lose in grip.
Reduction in brake failure risk – Alloy conducts heat extremely well which will help disperse hear produced from the braking system under extreme driving.
Cost – Obviously brand new wheels can be expensive,especially if tyres are required. But this can be an investment as in theory the resale value of the vehicle will improve.
Risk of theft – With your vehicle looking more desirable it may attract unwanted attention from thieves, but this can be counter acted by some security upgrade choices like a good quality set of locking wheel nuts/bolts.
How do I choose the correct Alloy Wheels?
It is important to consider what you wish to use the wheels for. We normally see customers that just want to change the wheels as they want to create a different look on their vehicle, but there are other purposes for fitting wheels than the visual change. Wheels are made in different ways, that can impact the weight and strength of the wheel. Also by changing the technical aspects of a wheel fitment, you can alter the driveability of a vehicle.
There are 3 main ways that wheels are produced, with very different characteristics but it is important to focus on the Cost, Weight and Strength.
So as you can see it is a case of determining which is more important, cost vs weight/strength, but bear in mind that most vehicles have Cast Alloy Wheels which are more than adequate for day-to-day driving.
2) Approvals / Certifications
When wheels are manufacturered there are 3 main tests on the market to help define the level of quality of the product or the manufacturer:
JWL / VIA - The tests for JWL and VIA are the same to certify the strength of a wheel, but with one important difference. A JWL test is self-certified by the manufacturer, so very easy to fake or falsify. All testing is done in house by the manufacutrer and relies on honesty. A VIA test is performed by the VIA governing body which requires the wheel to be sent to a VIA testing facility. VIA test results can't be falsified! To make things more difficult, there are many dodgy wheel manufacturers that will stamp the VIA logo into a wheel even if it hasn't been VIA approved.
TüV - In some european countries is it a requirement that wheels have a TüV approval, which is effectively a safety seal of approval. This sets a threshold that wheels have to have meet a set quality and be designed to certain design restraints to be deemed as safe. Passing TüV approvals can be expensive and time consuming, so this tends to only be something that is left to the big fish in the industry. There are however wheels that are designed to meet TüV approvals like but haven't undergone the expense of testing, which can give some great designs at a cheaper price with no comprise on quality.
Whilst an approval or certification isn't essential, it certainly is a testiment to the minimum quality of a product.
3) Intended Purpose
If your reason for buying new wheels isn't entirely for aethetics, then what else do you want from them?
• Are you looking for a light-weight strong wheel for Motorsport/Track use?
• Are you looking for an Off-Road wheel for rugged terrain?
• Do you need a highly load-rated wheel for commerical use?
• Are you simply looking for a cheap swap as your current wheels have deteriotated?
These are all elements that you can filter by on our website when searching for wheels. You can sort the wheels in price order, select a category such as Motorsport / Light-weight or Commerical Use. This will hopefully narrow the field for you in your search for new wheels.
4) Speed Of Delivery
Our website lists available stock from our warehouse, UK based suppliers and International suppliers - as such there will be different lead-times dependant on the stock location. Also there may be specialist machining work to be carried out prior to desptach which can affect the lead-time. The delivery timescale is something that you can filter by when searching for wheels, so if you have a time restraint on your order then please pay attention to this. Whilst opting for a quicker delivery will narrow the selection, hopefully we will have something suitable for you.
5) Vehicle Fitment
There isn't a universal fitment for wheels unfortunately and there are many technical elements that need to be matched in order to make sure the wheels fit your vehicle correctly. Luckily our website does the hard work for you, so this isn't something that you need to worry about. Simply enter your vehicle reg / vin number or manually select your vehicle, then we will match the wheels to your vehicle for you. Of course if you get stuck along the way then please feel free to contact our friendly sales advisors who will be happy to assist you and offer you all the technical help required.
6) Wheel Size
When you select your vehicle on our website, we will present you with a list of wheel/tyre combinations that were fitted as standard options by the vehicle manufacturer. We would always recommend to go no smaller than these sizes as there is a possiblity that any smaller wheels may foul on the vehicles brake assembly, but it's fine to go larger which our website will calculate and offer for you where applicable. Obviously there is a limit to how large you can go, for example 22" wheels on a Renault Clio would cause all sorts of problems and look ridiculous! There are also restrictions on wheel and tyre sizes that exist and are available, some tyre sizes won't be applicable due to load requirements, so there are limitations.
It is important to bear in mind that when you alter the wheel size, the tyre size will also need to be changed to compensate. You need to keep the overal diameter of the new wheels & tyres within tolerance of the original wheels & tyres, so when you increase the wheel size, the tyre profile (side wall height) will decrease to balance out. We recommend a tolerance of no more than 2.5% difference in overall diameter.
Also wheel width is a consideration as there is a limit to how wide you can go on the vehicle before running into problems.
Our website takes care of all this for you!
7 ) Colour / Style
There is a huge variety of colours and styles, all making a visual statement. Customers ask our opinion all the time of what design or colour to go for, but whilst we are happy to offer our opinion - it is an opinion down to personal taste. It's important to pick what you like, as you will be driving the vehicle, rather than focusing on what other people think. It's good to take inspiration and with the likes of social media sites like Instagram and Pinterest, there is certainly plenty of on-car images out there now.
Will by vehicle warranty or insurance be affected?
Generally speaking most insurance companies are understanding of a change of wheels on the vehicle, however it is considered a modification. Some insurance companies may adjust the premium as fitting new wheels can affect the value of a vehicle and it may draw unwanted attention from thieves. A You can always upgrade the locking wheel bolts/nuts to McGard Thatcham Approved ones, which we offer, and this will help keep the premium to it's lowest. it is best to speak to your insurance provider before placing an order as they may impose restrictions.
If your vehicle is still within warranty, then it is recommended to check with the warranty provider if fitting new wheels will affect the warranty. They may state that the wheels have meet a certain fitment criteria or be of a cetain level of quality.
Understanding the technical aspects
It can be pretty daunting trying to understand the technical side of Alloy Wheels, but luckily for you our website does all the hard work for you. It checks the technical suitably of the products for your selected vehicle and will only show you options that fit correctly. This means that you can literally browse away without worrying about any of the techical attributes. However there are of course customers looking for something specifically and all technical aspects are filterable and in some cases customisable on our website.
If you have any concerns over anything then please feel free to contact us, our sales team are considered the best in the UK for not only customer service but technical knowledge.
PCD (Pitch Circle Diameter) Explained:
This is the diameter of an imaginary circle drawn through the centre of the bolt holes. The PCD of the wheel should match the PCD that your car came with as standard.
PCD is measured in mm. e.g: 4x100 means the wheel has 4 bolt holes and the diameter of the imaginary circle through the bolt holes is 100mm. These details are shown in the 'Wheel Specifications' section on the main product page.
It is a common misconception that all 4 stud wheels will fitment onto a 4 stud vehicle, but it is also down to the stud distancing.
Whilst a wheel will generally have the corresponding number of bolt holes for the vehicle, there are some wheels that are cross-drilled. This means that they will have either 8 of 10 bolts holes, of which half of these will be applicable to the intended vehicle but the other half will have a different stud spacing intended for alternative vehicles. This is a great feature if you plan on selling the wheels in the future of using them on a different car (as long as the stud configuration is correct).
The Wheel Offset (ET) Explained:
The offset determines how far under the arch or how far towards the outer arch a wheel will sit. Each car has its optimum offset and a range within which the offset can be for the wheel to fit the car properly.
If the offset is too low for the range allowed, the wheel could stick out from the side of the car, if too high from what it should be the wheel may catch on the suspension or bodywork as it will be too far under the car.
This is due to the fact that if you put a wheel on your hub with a higher offset than before, the wheels bolting face will have to move further under the car to meet the hub, in extreme cases causing the wheel to sit too far under.
If you take a wheel and cut it in half and draw a line down the centre of the width of the alloy wheel the offset will be the distance between the back face (mounting face) of the wheel and the centre line that you have just drawn.
The offset is commonly shown as the letters ET followed by a number, eg: ET49. The offset is always measured in mm and can normally be found stamped on the back of the wheel or behind the centre cap (if fitted).
Using Wheel Spacers to alter the offset:
If the offset of a wheel is too high for your vehicle, in most cases spacers can be used to reduce the offset, pushing the wheel further out to make it sit correctly in relation to the cars bodywork and arches. Rimstyle.com automatically checks if spacers will be required, and if they are, it will tell you. This allows you to fit wheels to your car that aren't initially made in a direct fitment, widening your choice of wheels and is completely safe and road legal to do. However, if the offset of a wheel is too low compared to the offset your car needs, there is no way of rectifying this as they will already sit too far out from where they should be and can't be brought back under the car.
Wheel Width & Diameter:
The alloy wheel size is shown as follows: Wheel diameter x Wheel width - e.g: 15 x 6.5J
The width is the section between the tyre mounting flanges on the wheel / The diameter is the overal diameter of the wheel
Wheel Centre Bore and Spigot Rings Explained:
This is the diameter of the centre hole in the back of the wheel. It is crucial that the centre bore of the wheel locates properly on the lip on the hub of the vehicle to get a perfect fit. Most wheels work on a spigot ring locating system because most wheels have a centre bore bigger than the size of the hub lip allowing them to fit a wider range of cars. A spigot ring is fitted into the back of the wheel with an outer diameter the size of the centre bore, and an inner diameter the size of the hub lip to allow the wheel to be correctly located onto the hub and to fit tightly onto the vehicle for safety and comfort.
There are wheels that are hub-centric i.e. the wheel is manufactured with a centre bore to fit precisely onto a specific vehicle and in these cases we would not supply spigot rings as they would be unnecessary.
If the wheel does not locate onto the vehicle's hub assembly correctly it will cause a vibration on the steering wheel and can lead to bad wear on the tyres and bearings so if spigot rings are provided you MUST use them.