Disadvantages of upsizing your wheels
We are often asked about the benefits of tyre upsizing and many people believe that swapping their tyres for wider ones will result in a safer drive. This is because a wider tyre has a larger contact area with the road and hence delivers shorter braking distances and improved control on cornering. However, our years of experience tell us that there are many disadvantages to tyre upsizing so we always recommend that customers think carefully about their motivation for wanting to change their tyres before doing so.
Vehicle manufacturers select the combination of wheels and tyres that stringent testing demonstrates will create the optimal performance for their vehicles in the majority of driving environments and weather conditions. In some cases, a compromise is sought to balance cost and performance, but in general, it is hard to improve upon the combination recommended by your vehicle manufacturer.
Whilst it is true that wider tyres provide improved road contact, this comes at a price. Due to the increased rolling resistance, your vehicle will need to make more effort to move forward, which will reduce its fuel economy and adversely affect its acceleration. Wider tyres also cost more to buy and road noise is likely to increase, reducing driver comfort. Further, tyres that protrude from the vehicle body are more likely to be damaged by accidental contact with kerbs and potholes, requiring replacement sooner and again, costing more money. Wider tyres also disperse surface water less effectively and can increase the risk of aquaplaning.
If these disadvantages have put you off the idea of wider tyres, you may consider swapping to narrower tyres. Not surprisingly, narrower tyres will offer better aquaplaning resistance and lower road noise, but are less grippy and braking times are likely to be extended.
You may consider changing your wheels and tyres to get a thinner sidewall and larger wheels to try and improve performance and aesthetics, but there are some bigger wheels cons that you should be aware of. This will come at a significant cost and there is only so much leeway available, as your brake disks will still need to fit the new wheels. If you change the rim diameter, this can have a severe effect on your car's suspension. Tyres with a different diameter to that recommended by your vehicle manufacturer can also affect your speedometer, risking you speeding or driving too slowly for the conditions. The commonly accepted rule of thumb is that you shouldn't increase the wheel size by more than 1.5% or decrease it by more than 2%.
To get a professional opinion on changing the wheels, tyres or both on your vehicle, contact the experts at your local Protyre. You can book a free tyre check online via our website and should you wish to change your tyres, we stock a comprehensive selection from all of the major manufacturers, including Pirelli, Sumitomo and Bridgestone for you to choose from. We can provide tyre care advice, either for the tyres already fitted to your car, or for any new ones that you choose to have fitted.
