Should You Fit Wider Wheels & Tyres? (Benefits & Drawbacks)
Updated: Oct 16, 2021
Wider wheels and tyres can improve many aspects of handling but can also have some negative effects on handling too.
Below I go into more depth of the benefits and drawbacks of wider wheels and tyres and if you should fit them or not.
Table of Contents:
Should You Fit Wider Wheels & Tyres?
The advantages of wider wheels and tyres are usually a result of enhanced grip and stability.
However, wider wheels and tyres can also have some drawbacks such as the requirement to fit a wide-body kit, usually the tyres are more expensive and there are several other disadvantages.
It is also necessary to retain the stock diameter of the wheels and tyres in order for the suspension and speedometer to continue to operate properly.
As a general rule of thumb, it's okay to install a wheel that's around to 15-20 millimetres wider than the original wheels.
However, anything beyond 15-20 mm may require bodywork modifications such as fender rolling or wider arches.
Sometimes, the standard suspension may also have a hard time performing as normal with the additional weight of wider wheels and tyres, possibly requiring the installation of upgraded and stiffer coilovers or lowering springs.
You should read this guide about coilovers and lowering springs if you're after wider wheels and tyres.
Benefits of Wider Wheels & Tyres
Many of the benefits of wider wheels and tyres stem from enhanced grip and a wider track width.
The main benefits are listed below.
Enhanced Looks
The look and aesthetics of a car with wider wheels and wider tyres is usually more aggressive and stanced.
It signals performance and power, providing the setup is correct they can provide more of a benefit than just aesthetics.
Increased High-Speed Stability
High-speed stability is very important, wider wheels and tyres can improve upon this.
Due to a wider track width (the distance between the outside edges of a set of wheels on an axle) there is enhanced stability due to reduced body-roll and weight transfer.
This means a vehicle is less likely to become unstable, and therefore uncontrollable, in the event of a high-speed manoeuvre such as swerving or going over bumps in the road at speed.
Improved Grip
Wider tyres means more of a contact patch between the tyre and the road.
This increased surface area between the tyre and road will enhance grip and traction.
Enhanced grip allows for increased cornering speed and improved launches and acceleration, increasing track times.
Reduced Body-Roll
A feature of widened track width due to wider tyres and wheels is reduced body-roll.
Reduced body-roll, as mentioned earlier, improves high-speed stability.
However, minimising body-roll has other benefits too, such as improving steering response, cornering speed and reduces weight transfer.
Weight transfer is the shifting of a vehicles weight between the 4 wheels, a higher weight transfer due to body-roll can cause instability and swaying, possibly causing loss of traction and even roll-overs.
Therefore, minimising weight transfer as a result of reduced body-roll can increase stability, improving traction and enabling increased track times and speed.
Drawbacks of Wider Wheels & Tyres
Wider wheels and tyres have many advantages; however, it's not all good.
There are several disadvantages to increasing track width and wheel width, such as listed below.
Reduced Steering Sensitivity
A wider track width as a result of wider wheels and tyres can reduce the steering sensitivity.
Sometimes this is not obvious due to the reduced weight transfer improving the steering sharpness but the turning radius will be larger, making parking and navigating tight roads slightly more difficult.
However, this issue can be overcome with a properly setup suspension and staggering the front and rear track width ratio.
Reduced Fuel Economy & MPG
Wider wheels increasing rolling resistance, this will reduced fuel economy and mpg.
This gets worse the wider your wheels and tyres become.
If your wheels are so wide that you need to install a wide-body kit, the increased air drag will further reduce fuel economy.
There is also slightly extra weight with wider wheels and tyres, which will over time increase fuel usage.
More Expensive Tyres
The bigger and wider the tyres, the more expensive they will be.
You should bear this in mind when considering running wider wheels or tyres.
Also, you may need to start upgrading certain components in order to handle wider wheels, this adds to the cost even further.
Possible Body-Work Modification Needed
As mentioned previously, if the wheels are significantly wider you may be required to roll out and flare the arches or install a wide arch kit.
If you are lowering your car, you may even have to cut or grind down the original arches in order to fit wider wheels.
This can be avoided by keeping the wheels under around 15-20 mm wider than standard, depending on the car.
Extra Unsprung Weight
Unsprung weight is anything not being held up the cars springs or dampers, such as the control arms, wheels, brakes etc.
Minimising unsprung weight here is crucial, even grams of reduced weight counts.
Installing wider wheels and tyres adds significant weight to the unsprung mass of a car, affecting braking, acceleration and cornering.
This effect can be reduced by using lightweight wheels, lightweight lug nuts and lightweight brake kits.
Wider Tyres vs Stretched Tyres
You may have heard of people using stretched tyres on wider wheels instead of the correct size tyre.
A technique known as tyre stretching is the practise of fitting a tyre on a wheel that is narrower than the wheel itself.
When the sidewalls of the tyre are pushed over to the outsized rim, they essentially lower the profile of the tyre at the same time, rather of being about 90 degrees square to the tread pattern.
This can cause problems such as reduced weight capability of the tyre, de-beading and even invalidates some insurance policies.
Therefore it is important to use a wider tyre with a wider wheel, instead of stretched tyres.
Wider Wheels vs Wider Track-Width
Sometimes people want to fit wide-body kits and have a wider track width, but may not want to install wider wheels and tyres.
This is when people use wheel spacers.
Wheel spacers can widen the track width of the car without increasing the tyre width or wheel width.
Although fitting wheel spacers is the cheaper and easier option, it is not perfect.
There is a possibility of increased stress on certain suspension and drivetrain components, such as driveshafts, struts and wheel bearings etc.
Overall, small wheel spacers, such as those of around 5mm, can be beneficial for increasing brake clearance, tuning the track width of a car and filling in an arch gap.
But large wheel spacers such as those of around 15mm and upwards can cause extra strain on components and have the same drawbacks of increased track-width without the benefits of wider wheels.
Make sure you fit wheel spacers properly, visit this tutorial to ensure you properly fit wheel spacers.
Conclusion
Increasing the width of wheels and tyres can improve many aspects of a cars handling such as grip, stability and overall handling.
There are also some disadvantages of increasing tyre and wheel width such as it being more expensive for tyres, harder to drive around the town and in narrow areas and reducing fuel economy.
You may also have the modify the body-work when fitting wider wheels and tyres.
