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According to figures from the RAC, at the end of June 2023, there were 41.2 million licensed vehicles in the UK, an increase of 1.3 per cent compared to the end of June 2022. Cars make up the majority of licensed vehicles; however, in the last 25 years, van traffic has seen the fastest growth in percentage terms of any motor vehicle, increasing 106 per cent to 55.5 billion vehicle miles in 2019. This rapid rise in van traffic now means that van traffic as a proportion of all motor vehicle miles has increased from 10 per cent to 16 per cent over the same period.
When selecting a vehicle, the wheels aren’t commonly considered to be the most important feature. A lot of drivers are tempted to disregard the overwhelming importance of such things like wheel rims and tyres, thinking that all things related to the engine are more important. However, vehicles are complex mechanisms, and every single component matters as much as the next one. Without each other, the vehicle would not be able to be driven. If unsuitable wheels are chosen, this can adversely impact your driving experience. They may not be appropriate for how you use the vehicle or might detract from its appearance. Wheels and tyres are especially important because they are the only things that support your vehicle and separate you from the road.
Introduction to Wheel Selection
Wheels are one of the most critical parts of your vehicle, as they help convert the engine’s power into movement and serve as the point of contact between your vehicle and the road. The various components of the wheel include three main parts: the tyre, the rim, and the hub. The tyre, which is the width of the wheel, goes around the rim and gives the wheel grip on the road surface. The hub is where the wheel attaches to the axle of a vehicle.
Wheel rims are one of the most popular replacement vehicle parts around. Aside from the aesthetics, they are also a fairly common replacement made through necessity. Wheel rims most often need replacement after damage or, in the worst case, a road accident.
Wheel rims are generally available in two main types, alloy and steel. As the names suggest, alloy wheels are made primarily of aluminium, and steel wheels are made of steel.
Steel rims are strong, durable and easy to keep clean, but aren’t as shiny or as lightweight as alloys. The basic way in which steel wheels are produced means that there is very little flexibility when it comes to design or any type of artistic flare. The unattractive nature of pressed steel wheels is usually enhanced by fitting hubcaps with some badging to disguise the raw metal and imitate a set of more expensive and stylish alloys.
Alloy wheels are shinier but aren’t as durable, with more susceptibility to scratches, dents and dirt. The freedom of design has led to some truly spectacular looking alloy rims over the years, but the softer material also opens the door for some fairly catastrophic results after kerbing, i.e. hitting a kerb with a vehicle wheel, leading to possible damage to the wheel and tyre. Based on an aluminium or magnesium construction mixed with nickel, alloy wheels provide a much lighter package when compared with a steel wheel of the same strength, and can be cast in full by pouring molten alloy into a pre-made mould.
The wheels are then completed with tyres. The tyres on your vehicle do the crucial job of connecting you to the road, so selecting the right set is vital to your safety and comfort.
Factors Influencing Wheel Selection
Vehicle modifications refer to any changes or additions made since the vehicle left the factory, which doesn’t include manufacturer options that are factory-fitted. Drivers typically buy new wheels for two reasons: they want to replace damaged wheels, or they want to give their vehicles a new and improved look. Wheels fitted to a vehicle make a big visual difference, and selecting the right wheels to complement a vehicle can be a great upgrade. It increases the visual appeal of the vehicle but it can also have a very positive improvement to the driveability.
Many people make the mistake of believing that the role of the wheel is purely aesthetic, but they would be wrong. Wheel rims and tyres affect the way your vehicle drives. Good wheel rims will be properly fitted and will make all the difference to the way your vehicle performs. Not all wheel rims will fit all types of vehicle; it depends heavily on the vehicle make, model, year, etc. Most modern-day vehicles come with factory-fitted alloy wheels. Steel wheels are often found on entry-level and older vehicles.
There are a number of common wheel rim terms that you should know before selecting wheel rims. These are:
Bolt pattern – otherwise known as a lug pattern or bolt circle, this is the diameter of the circle formed by the wheel lugs, as seen on the exterior of the wheel rims. This is comprised of two numbers. The first is how many bolt holes are on the wheel and the second describes the diameter. For instance, 5×108 would indicate a 5-lug bolt pattern within a 108mm diameter. Your vehicle’s make and model possesses a unique bolt pattern, meaning any wheel rims purchased must be compatible with the specific type.
Hub centre bore – this is the central hole that keeps the wheel centred on the hub of the vehicle.
Torque – wheels are always installed using a torque wrench, and freshly installed wheels should always be re-torqued after the first 100km in order to ensure that everything remains tight.
Offset – this refers to the distance from the hub mounting surface of the wheel through to its centre line. There are three types of offset: zero, positive, and negative. For zero offset, everything is even. Positive offset means that the mounting surface is leaning towards the front or wheel side of the centre line. Negative offset means that the mounting surface leans towards the back or brake side of the centre line.
Key to proper performance is ensuring that your wheel rims fit perfectly. Wheel rims that are too big for your vehicle will reduce stability and proper suspension, creating poor steering control. On the other hand, wheel rims that are too small don’t support a vehicle well. There is one more important thing to remember if you have decided to opt for bigger wheel rims than those your vehicle currently has – make sure your new wheel rims do not come into contact with any stationary parts of your vehicle. Doing so could have a negative impact on vehicle handling as a result of unwanted friction.
A wheel rim’s weight is another factor to consider when selecting wheels. Your vehicle’s suspension cannot counteract the weight of the wheel rim, so the heavier it is the less agile your vehicle will be. The material the wheel rims are made of has perhaps the biggest impact on wheel rim weight. As a result, it is a good idea to look for light rims that nevertheless meet your needs for durability and aesthetics.
Other considerations include:
Wheels make precise steering possible, and if any of them are defective, you won’t have complete control over your vehicle and this may result in an accident. Since steel wheels are stronger, the possibility of cracks in an accident is very low; they may bend upon impact, hence they are safer than alloy wheels on impact.
Although alloy wheels are strong enough, they are prone to cracks upon impact. It may be fatal if you are driving at high speeds. However, alloy wheels conduct heat faster, which boosts braking ability. Stopping the car becomes safer and easier on long trips and rugged roads, and you don’t have to worry about damaging the brakes.
Handling and performance
Larger wheels need larger tyres, which have a wider contact patch against the ground. This delivers better grip and handling, giving you better traction and shorter braking distances. Alloy wheels contribute to shorter braking distances, quicker acceleration and better manoeuvrability. They are also gentler on your vehicle’s suspension system, which is vital for steering control and comfort.
Because steel wheels are thicker, they require tyres with a high profile. Tyres with thicker sidewalls have more rubber that acts as shock absorbers, which gives you a more comfortable ride. With steel wheels, your vehicle’s centre of gravity is lower, which affects acceleration and braking. Your suspension is also a bit more stressed with steel wheels.
The bigger and heavier the wheel, the more effort and fuel it requires to move your vehicle forward. Because alloy wheels are lighter than steel wheels, your engine doesn’t have to consume as much fuel while moving.
Because they are heavier, steel wheels create more rolling resistance, which is made up of the forces that keep your vehicle from moving forward. Your engine uses more fuel with steel wheels, which is bad for the environment and your budget.
Cost and durability
Alloy wheels are often more expensive due to costlier materials and complicated production techniques. They are not as durable as steel as they can easily bend or crack during road impacts. Although they are repairable, the repair process is complex and expensive. They are also more prone to corrosion and oxidation, particularly in winter. When this happens, tiny bubbles form on the flange or the rim’s edge. With oxidised wheels, tyres can lose pressure, causing an unstable ride. However, alloy wheels can now be winter-proofed, but this can mean additional costs. Another cost to consider with alloy wheel rims is your insurance premium. Standard alloy wheels won’t impact insurance, but if you upgrade them or even paint them a different colour, your premiums could rise. This is because better alloys may increase the likelihood of your wheels being stolen, which is a common insurance claim.
Steel wheels are best known for their durability. Because of their straightforward materials and manufacturing process, steel wheels are more affordable than alloy wheels. Steel is one of the stronger metals around. Steel wheels are cut on a press and welded, making them especially strong. They can’t be cracked or bent easily, making them the perfect option for winter driving. Steel wheels are easily repairable.
Both the alloy wheel rims and steel wheel rims serve the same purpose, but the appearance and construction are different. The former is aesthetically pleasing but expensive, whereas the latter is inexpensive and practical. If your reason for buying new wheel rims isn’t entirely for aesthetics, what else you want from them will need to be factored into your choice, such as:
- Are you looking for lightweight strong wheel rims for motorsport/track use?
- Are you looking for an off-road wheel rim for rugged terrain?
- Do you need a highly load-rated wheel rim for commercial use?
- Are you simply looking for a cheap replacement as your current wheel rim(s) has deteriorated?
Tyres are the other component of vehicle wheels, and are the only component of your vehicle that actually touches the road, so they are critical for safety when driving. Selecting the right tyres for your vehicle can seem complicated and confusing, especially when you consider different aspects such as performance, usage and driving habits. Things such as how many tyres you need, the size and type of your vehicle, how you drive, and how you intend to use the vehicle, will greatly impact which tyres are suitable for your vehicle and all go into making a decision to buy a particular tyre or set of tyres over another.
According to the British Tyre Manufacturers’ Association (BTMA) the principal constituents of tyres are typically:
- Elastomers 42%
- Carbon black and silica 28%
- Steel 12%
- Oils 6%
- Textile 5%
- Zinc oxide 1%
- Sulphur 1%
- Other ingredients 5%
A bewildering choice of replacement tyres is available, so when selecting the most appropriate tyres for your vehicle, first you need to understand the difference between radial ply and cross-ply tyres, and their relative strengths and weaknesses is important when it comes to deciding between the two. The significant tyre construction difference between the two tyre ply types is the way that the ply cords are arranged. In cross-ply tyre construction, the cords are arranged at a 45-degree angle to the centre line of the wheel and criss-crossed. In a radial ply tyre, the cords are arranged at a 90-degree angle to the centre line of the wheel and overlap.
Cross-ply tyres have stronger and less flexible sidewalls as a result of this construction difference, which is advantageous in protecting the inner tube that is essential in cross-ply construction. As radial tyre construction does not require an inner tube, the flexibility of the sidewall is advantageous in terms of absorbing vibrations and generating less heat.
The advantages of radial tyres are significant. They offer improved ride comfort and handling, greater fuel efficiency, are significantly safer than cross-ply tyres, and since the 1970s, they have become standard on all road cars in the UK.
The disadvantages of radial tyres are the vulnerability of the flexible tyre sidewall to damage when overloaded or underinflated, or to impact damage, as well as the increased cost, though radial tyres will last longer before needing to be replaced. Cross-ply tyres are now most commonly used for off-road vehicles, construction/agricultural vehicles and classic cars.
Before you decide about tyre brands, must-have features, and performance specs, you will need to ensure the tyre is a match for your vehicle. The original equipment tyres are carefully matched to the vehicle by the tyre and vehicle manufacturers. Vehicle performance and comfort will be altered if replacement tyres are not of a similar specification. You will need to measure up the following:
- Section width – the overall width of the tyre, measured in millimetres.
- Wall thickness – recorded as a percentage ratio of the tyre’s width to its height. A low-profile tyre has shorter sidewalls that aren’t as flexible as regular profile tyres. Shorter sidewalls increase your road holding and grip tight around corners. However, low-profile tyres are generally more expensive and are less comfortable than regular varieties.
- Type – either radial (R) or ply (P).
- Rim diameter – the length across the inside of the rim, in inches.
- The load rating index – is the maximum load the tyre can carry, shown as an indexed number representing weight in kilograms.
- Speed rating index – displayed as a letter, representing a maximum speed in mph.
You can find all this information recorded as a single code on your tyre’s sidewall. Failing that, the tyre codes for your vehicle are specified in its handbook, or as a sticker on the driver’s side door.
The technical spec for your particular vehicle will help to whittle down your search choice. You will now need to consider other things such as:
Fuel economy – tyres directly impact the amount of fuel that your vehicle uses. This is because different treads have different degrees of rolling resistance. The lower the resistance, the less fuel is consumed.
Wet grip – tyre treads quickly evacuate water away from the wheel, thereby reducing the risk of aquaplaning; the higher the grade, the shorter the braking distances are in rainy weather.
Noise – every tyre tread is unique, and as such, some prove louder on the asphalt than others. The fewer bars, the quieter the tyre. Only tyres with two bars or less will meet future legislation.
Tyre labels are one of the simplest ways to gauge how a given tyre performs. Tyres sold on the UK market must have labels that give information about:
- Fuel consumption
- Wet grip
- Noise classification
Finally, when choosing tyres you may want to consider such things as:
Seasonal tyres – while all-season tyres are effective in milder climates when the conditions between summer and winter aren’t too different, in some areas seasonal tyre changes are required by law. Winter tyres, or cold weather tyres as they are also commonly known, can play an important role in ensuring you stay safe on the roads during the more severe winter months. Winter tyres are designed to work best in conditions below +7°C, so even in wet and icy conditions, you will benefit from their superior grip and handling. Summer tyres are designed and engineered to work best during the warmer summer months. They are created with a specific tread pattern for optimal performance on both dry and wet roads when the air temperature is above +7°C.
Specialist tyres – if you have a high-performance sports car, SUV, 4×4, or campervan, you will get the best results from your tyres if you choose models designed specifically for your vehicle. For example, 4×4 tyres are designed for off-road use and are excellent on difficult terrains such as soft ground and steep inclines where normal tyres aren’t up to the task and can get stuck. 4×4 tyres also demonstrate better grip in adverse weather conditions like snow and ice than conventional summer tyres.
Run-flat tyres – these tyres keep you on the move if you suffer a puncture. However, they are not designed for driving hundreds of miles; instead, they give you enough time to get to safety. It is crucial, however, that you only fit run-flat tyres to vehicles that feature the right technology. All vehicles fitted with run-flat tyres require a tyre pressure monitoring system (TPMS) which alerts the driver should the tyre receive a puncture or there is a sudden drop in tyre pressure. Without TPMS, fitting run-flat tyres could be a major safety risk as the motorist could continue driving, unaware there is an issue with the tyre.
Cost – whether to select budget or premium tyres will depend upon your motoring needs. It is never a case of compromising safety or reliability when you opt for budget tyres, you are merely forgoing design quirks that elevate handling and performance. The lifespan of a tyre often depends on what and where you drive. Premium tyres are more advanced and offer better fuel economy. If you are unsure, go with the highest quality tyre that you can afford.
Wheel Maintenance Basics
Keeping your wheels in good condition is essential for staying safe on the road. Wheel maintenance begins with the tyres. There are two basic tyre maintenance checks that you should be doing weekly:
- Assessing the tread
- Checking your tyre pressure
Tyre treads have a direct impact not only on the performance of your vehicle but also on its overall safety, especially in poor weather conditions. The legal minimum tread depth is 1.6mm, so it is important to make sure that it does not go below this limit. If the tread is at or below the minimum depth, your tyres will need to be replaced straight away. Remember, driving a car with tyres below this limit is not only illegal but also extremely dangerous and will cause your vehicle to fail its MOT test.
Checking tyre pressure is essential for road safety, driver performance and fuel efficiency. If it is too high, you run the risk of excessive wear, poor vehicle handling and low suspension. Too low, and you will likely experience punctures, poor fuel efficiency and increased rolling resistance. Either way, it is dangerous. So, knowing how to check and inflate your tyres is critical to your day-to-day driving. You can use the gauge provided at a petrol station to check tyre pressures. Usually, you will see a machine for air and water with the gauge attached. Otherwise, you can buy an LED tyre pressure gauge. The recommended tyre pressure measurement for your vehicle is found in your vehicle handbook, on the dashboard, or for newer vehicles, inside the fuel cap, or on the driver’s door. Before you start, make sure the tyres are cold. If they are too warm, you may get inaccurate pressure readings.
It is also important to do a physical check of the tyres and look out for any signs of unusual wear or damage. This can include cuts, bulges or any objects that may have punctured the tyre. If you notice any of these problems, you will need to get them checked by a professional mechanic and repaired if necessary. In some cases, the tyre will need to be replaced altogether with a new one. If your vehicle has a spare tyre, check that one as well.
Regularly inspecting your wheel rims can help you catch any problems early and prevent further damage. Look for signs of corrosion, pitting or other damage, and address these issues as soon as possible to prevent them from worsening. You should also inspect your wheel rims for cracks, bends or other structural damage. If you notice any of these issues, it is important to have your wheels repaired or replaced immediately, as they can compromise the safety and performance of your vehicle.
Common Wheel Problems and Solutions
Your wheels need to be correctly aligned as per the manufacturer’s guidelines. Misaligned wheels are a common source of uneven tyre wear and also reduce the lifespan of the tyres and reduce fuel efficiency. You can check your wheels’ alignment by driving down a straight and quiet road; and if you need to apply slight pressure on the steering wheel to keep it going in a straight line, then your wheels will need to be realigned. Also, your steering wheel should be perfectly centred. One simple way to check your wheels’ alignment is by looking at the emblem on your vehicle’s steering wheel. If the emblem doesn’t look level whilst driving down a straight road, this indicates that your steering wheel is not centred. When your vehicle has been realigned, the steering wheel will be centred, and you will have more control of your vehicle.
If your steering wheel shakes mid-drive, especially at certain speeds or while turning, this is an indication that you need to get your wheels balanced. Wheel balancing, also called tyre balancing, ensures that the weight of a wheel and tyre assembly is distributed evenly for a safe and smooth ride. Wheel balancing is essential for vehicle safety as well as making the most of your tyre investment. Wheel balancing and alignment are NOT the same things. They are two completely different processes. Unbalanced tyres can be caused by:
- Flat spots, especially if you haven’t driven the vehicle or moved it in a while
- Hitting a kerb, bump or pothole hard causing the loss of a wheel weight or further tyre and wheel damage
- Colder weather because it can cause your tyre(s) to deflate
- Your tyre has a puncture and needs repair or replacement
Cracked wheel rims are a common problem. The most common cause of cracked rims is driving over potholes or other uneven surfaces. This can send a juddering force through your vehicle and crack the wheel rim. Sometimes, the damage may be fairly superficial and can be fixed with a simple weld. However, in other cases, the damage may be more serious and require the replacement of the entire wheel rim.
Bent wheel rims also occur when the impact of hitting a pothole or other object is too much for the wheel rim to bear. The result is a wheel that is out of alignment and can’t rotate smoothly. Not only does this make for an uncomfortable ride, but it can also cause premature tyre wear.
A slow puncture will usually be easy enough to spot, as your tyre will deflate regularly. Due to the slow rate of air being released, you may not necessarily know you have a puncture at first as it is difficult to detect or hear straightaway; you may even make it all the way to your destination without realising it. The best way to avoid slow punctures is to regularly conduct visual tyre checks.
Professional Services and DIY Tips
Maintenance and repairs for anything more serious than mild damage is usually best left to the professionals, unless you are proficient at car maintenance. For example, the process of dynamic wheel balancing begins with mounting your tyre and wheel assembly onto a computerised tyre balancer / tyre balancing machine. The machine will centre and spin the tyre to measure the imbalances. These measurements help the fitter identify the best spots to install tyre weights for a properly balanced tyre and wheel assembly.
You should get professional wheel alignment when:
- Installing new tyres
- For newly replaced suspension parts
- You have encountered a road hazard such as potholes, road debris etc.
- Your tyre(s) gets older
Damage to wheel rims and wheels that are heavily damaged will require professional repair or replacement. If you start hearing thumping noises, experiencing strange vibrations, or feel that your handling is off, you will need to have your wheels professionally checked.
One of the most important things you can do yourself to maintain your alloy wheels is to clean them regularly. Brake dust, road grime, and other contaminants can accumulate on the surface of your wheels, leading to corrosion, pitting and other damage. To prevent this, clean your wheels at least once a month, or more often if you drive in a particularly dirty or corrosive environment. When cleaning your alloy wheels, use a gentle, non-acidic cleaner that is specifically formulated for alloy wheels. Avoid harsh detergents or acidic cleaners, as these can damage the surface of your wheels. You can also use a specialised wheel cleaner that is designed to dissolve brake dust and other stubborn contaminants.
Everyone kerbs a wheel at some time. It is possible to repair light damage with an over-the-counter alloy wheel repair kit comprising sandpapers, a filler, primer and paint. You may want to apply a lacquer on top, depending on the wheel’s finish.
Legal and Safety Considerations
In the UK, a legal tyre must meet specific requirements to be considered roadworthy. Here are the key legal requirements for tyres:
- Tread depth – the minimum legal tread depth for a car is 1.6mm across the central three-quarters of the tyre and around the entire circumference. It is recommended to replace tyres when they reach the legal limit and consider replacing them at 3mm for improved safety.
- Condition – tyres must be free from any bulges, cuts or other forms of damage that could compromise their structural integrity.
- Type approval – tyres must be of an appropriate type and have the correct speed and load ratings suitable for the vehicle.
- Run-flat tyres (if fitted) – if your vehicle is equipped with run-flat tyres, they must be in good condition and functioning correctly.
- Mixing tyre types – it is generally advisable to avoid mixing tyre types, i.e. radial and cross-ply, on the same axle or across the vehicle unless the vehicle manufacturer specifically permits it.
- Winter tyres – there are no specific legal requirements for using winter tyres. However, if you choose to use them, they must meet certain standards and display the M+S (mud and snow) or snowflake symbol on the tyre sidewall..
- Tyre Pressure Monitoring System (TPMS) – if your vehicle is equipped with a TPMS, it should be in proper working order.
Wheels and tyres are also inspected as part of the annual vehicle MOT if the vehicle is over three years old.
Regularly check the Driver and Vehicle Standards Agency (DVSA) for the most up-to-date information on legal tyre requirements.
If you are stopped by the police with the incorrect pressure, or with an illegal level of tread depth, you could face police action. This is also true if you have cracked or bulging tyres, where the damage creates an unsafe environment for all road users. The police can take several actions depending on the circumstances, including:
- Issuing a penalty notice
- Prohibition notice
- Vehicle impoundment
- Court proceedings
Driving with illegal tyres is taken seriously as it poses a risk to road safety.
Latest Trends in Wheel Technology and Maintenance
The automotive sector is undergoing its most significant era of change in the past 50 years as it continues to move towards zero-emission vehicles.
Implementing technologies such as artificial intelligence and digital scanning technology can allow tyre manufacturers and dealers to efficiently and accurately gather data to improve the driving experience. Using AI and computer vision to measure tyre tread depth will also become more prominent in the automotive industry in the next several years.
With AI-enabled technology, tyre technicians and drivers can measure things like tyre tread, creating a 3D model of each tread using their mobile device. This allows tyre dealers to have precise digital measurements that can be instantly stored in a database and shared with customers. With AI, tyre dealers can make online tyre buying easier by creating a simpler shopping experience with tyre scanning, giving shoppers the option to use their smartphone to quickly scan tyre sidewall details, such as size and load rating, and find the right tyres for their vehicle.
The pneumatic tyre, which is a round rubber hoop filled with air, has been the basic structure and design for over 140 years. The first practical pneumatic tyre was made in 1888 in Belfast, by John Boyd Dunlop, and appeared on the market in 1895. Now multiple companies are developing, and even producing, non-pneumatic or “airless” tyres. Tyre manufacturers say they are working on new designs for cars, but nothing is definite in terms of product release dates.
From electric vehicles (EVs) to self-driving cars, wheels and tyres are ever evolving in design and characteristics to meet the needs of new driving technology.
In the UK, potholes remain the biggest hazard to vehicle wheels and tyres. According to the RAC, in 2022/23, the total number of potholes filled in was 1.4 million, down from 1.7 million last year but still equivalent to one pothole being repaired every 22 seconds in England and Wales. When you notice potholes, you can report them through the following sites www.fillthathole.org.uk or www.fixmystreet.com