It’s no surprise that when people want to improve the look of their car, the first thing they’ll often look at are new wheels. Customising your wheels is the easiest way you can personalise your car and express who you are, but it’s an easy thing to get wrong and your choice of wheels can either make or break the look of your car. Get it right and they’ll add visual appeal to your car and improve performance. Get it wrong and it’ll be one of the most expensive mistakes you’ve ever made.
Luckily, car enthusiasts today are truly spoilt for choice when it comes to selecting wheels. No matter what you drive, there’s a multitude of wheels available in retail stores, or more temptingly, available even cheaper online. But before you pull the credit card out and ‘Buy it now’, there’s some important details you need to consider first.
No matter what wheel you’re looking at, there’s several measurements you need to take note of. They are Wheel Diameter, Wheel Width, Offset & Bolt Circle, plus the construction of the wheel itself. Let’s look at each aspect in depth.
The diameter of your new wheels is an important factor to consider when replacing the original ones on your vehicle. Explained simply, the diameter is the measurement of how big the circle of the wheel is – but it isn’t measured across the face of the wheel as commonly thought, but instead from the bead seats – which is surface where the tyre fits onto it. It is important that the overall rolling diameter of your vehicle’s tyres remain the same, so any increase in wheel diameter always means you’ll need to go for lower profile tyres (reducing the tyre’s sidewall height) so that the same overall rolling diameter is maintained.
What you need to remember here is that upgrading to a larger diameter wheel will dramatically improve the look of your vehicle and improve handling responsiveness. But on the flip side, you’ll see a reduction in ride comfort due to the lower profile tyres required to maintain the overall rolling diameter. Your car will tend to ‘jiggle’ more over small road imperfections and hit harder through pot holes or other road hazards. Generally it is advised to stick to the same size wheels your car came with, or limit your wheel increase to 1 or 2 inches larger.
On the flip side, selecting a smaller diameter wheel will improve the ride comfort of your vehicle, at the expense of some handling responsiveness and visual aesthetics. While it is rare for people to downsize their wheels, it is also important to check firstly whether the smaller diameter wheels will clear your brake calipers.
It is important to compare the width of your new wheels to the original equipment items fitted to your vehicle. Wheel width must be looked at in conjunction with wheel offset, when determining how the wheels will fit under your vehicle’s guards and also what size tyres you can fit to them.
Running narrower wheels tends to improve vehicle ride comfort and cornering in the wet, at the expense of traction in the dry due to the required narrower tyres. Conversely, wider wheels allow wider tyres to be fitted, improving dry traction (and off-road performance for 4WD vehicles) at the slight expense of wet cornering (increased chances of aquaplaning) and some ride comfort.
As you might have guessed, wheel width directly affects the width of the tyres you should have fitted to your vehicle. Selecting wider wheels with narrower tyres may result in more vibration and a reduction in ride comfort because the side-walls of the tyre are under tension, as they stretch onto the wheel. Selecting wider tyres will improve ride quality and handling, but may cause the tire to rub on the body or suspension components while turning.
On the other side of the coin, selecting wheels that are narrower than the tyres may result in poor handling as the tyre distorts sideways under fast cornering. As a result, it is vital to get the wheel width correct right from the start, to avoid running into these problems.
Offset & Bolt Circle
The offset of a wheel determines how far in or out the wheel sits in relation to the hub and the guard/wheel arch. Each vehicle has an optimum offset range and the further you deviate from it, the higher the chances are of the wheel not fitting properly.
When compared to the offset of your vehicle’s factory OEM wheels, an aftermarket wheel with a negative (higher) offset will stick out further from the side of the car, potentially allowing it to hit the front guards whilst cornering or going over bumps. Alternatively, an aftermarket wheel with a positive (lower) offset will sit further inwards from the side of the car, potentially causing it to hit or rub on suspension components or the inner walls of the wheel well.
Let’s look at an example. Say your car has 18×7.5″ +45 offset wheels as standard, and you feel they sit a little too far inside the guards. You estimate your new wheels would look better if they sat 15mm further out, and there appears to be plenty of space inside the guard to accommodate this. This means the wheel you’re after is an 18×7.5″ with an offset of around +30.
When upgrading your vehicle’s factory OEM wheels, it is also vital that your new wheels feature the exact same bolt circle measurement. You might have seen bolt circles of 5×114.3 or 6×139.7 – what these list are the amount of wheel studs and the diameter of the circle they’re arranged on. So a 5×114.3 wheel has five wheel studs arranged along an imaginary 114.3mm diameter circle around the centre of the wheel.
Alloy or steel?
Wheels traditionally are built from two types of material, alloy (aluminium) or steel. On lower-spec passenger vehicles, manufacturers often use steel wheels with plastic wheel covers as a means of cost cutting, allowing the vehicle to be put on sale at a lower price. Higher-spec models will almost always be offered with larger, more attractive looking alloy wheels. But when it comes to 4WD vehicles, the choice is not quite as clear cut.
Firstly we must look at the pros and cons of each:
- Cheaper than alloy wheels.
- Will never split or crack.
- May bend on hard impacts, but can be hammered back into shape as an emergency fix.
- Heavier than alloy wheels, decreasing vehicle performance and increasing fuel consumption.
- Available in fewer styles and colours.
- Stronger than steel wheels.
- Available in a wider range of styles, finishes and sizes.
- Lighter than steel wheels, improving vehicle performance and fuel economy.
- May crack or split from very hard impacts, are often non-repairable.
- Are usually more expensive than steel wheels.
So which is best?
With the above points in mind, alloy wheels are almost always the perfect choice for passenger vehicles. Their stronger construction and lighter weight means passenger vehicles will see improvements in handling, performance and fuel economy, whilst also looking better visually.
For 4WD vehicles, the advantages of steel or alloy wheels can be used to the vehicle owner’s advantage, to suit their kind of driving. For people who often drive their 4WD through harsh, remote conditions, the rugged dependability of steel wheels will be an attractive proposition. Their inherent strength and ability to bend (rather than crack) means you’ll never be left stranded in the event of a hard impact.
For everyone else, alloy wins almost every time.
Lastly, there’s the matter of style..
After you’ve considered all of the points above, you’re left with the easiest part – picking a style you think will suit! Beauty is in the eye of the beholder, so as such there aren’t really any tips I can give you here, except my own opinions.
- For white or lighter coloured cars, I think darker coloured wheels such as black, gunmetal grey or silver wheels look best.
- For silver or coloured cars, safe bets are grey / alloy coloured wheels, or a colour which contrasts with the colour of your vehicle. Black can also look okay.
- For black or darker coloured cars, sometimes going for brighter wheels can really set the car off – think silver or chrome. Black wheels on a black car rarely looks good, unless it’s an AMG Mercedes or other performance vehicle.
You might not agree with my suggestions above, but hey, that’s what makes the world so interesting. If we all drove the same vehicles with the same wheels the world would be an incredibly boring place. Choose your wheels wisely and according to your own tastes you can’t go wrong – and if in doubt, consult a professional.