A vehicle's tyres play a crucial role in the overall design, performance, and handling. A simple process like upsizing the tyres, or getting your car fit with tyres that are one size bigger may add heaps of design benefits.
But with all good things, come a set of disadvantages. Here are the important advantages and disadvantages with upsizing you car tyres.
Let's take a look at the advantages, or the pros first.
Like we had mentioned earlier, tyres play an important role in the overall design of a vehicle. Upsizing tyres on a car gives it a sporty look, while on SUVs, the uplift the overall ruggedness of a vehicle.
2. Better Handling
Bigger tyres mean stiffer sidewalls and wider thread. This directly translates to better cornering and handling.
3. Better Contact Patch
Similar to gaining better handling, the contact patch goes up as well, since upgrading the size means there's more rubber. Better contact patch also means better braking.
Now having seen the advantages, let's take a look at the disadvantages, or the cons of upsizing the tyre.
Let's start with basics. Bigger the tyre, higher the cost. High-end cars usually come with bigger rim sizes, and to suit such cars, a lot of technical details go into making tyres, which turn out expensive.
Bigger tyres fitted on a vehicle simply means adding more weight. Heavier the tyre is, the more strain the engine takes, affecting the mileage, performance, and acceleration.
3. Bumpy Ride
A car's suspension setup is designed to take a particular tyre size. If the tyre has been upgraded to a size bigger than what the company has recommended, the suspension will not be able to soak up bumps as efficiently compared to a vehicle with the original tyre size. Also, if the wheel wells do not have sufficient space, you would risk the tyre scraping against the vehicle's body.
4. Hard Steering
While handling improves with a bigger tyre, the steering may become harder if the tyre size is beyond a particular size. This in turn will make the car handle very poor and the steering feedback (which is necessary) will not be as sharp as how it was with the original tyre size.
5. Early Tyre Wear
Up sizing the vehicle's tyre will lead to early tyre wear. This could be because of any of the above mentioned facts like heavy steering, wheel scraping against the vehicle's body, and the fact that lower sidewalls will wear out the tyre tyre faster than expected.
6. Speedo Error
If a car, say for example comes with stock 16-inch wheels and has been upgraded to 19-inch wheels, the speedo reading will not be accurate. This is because the speedometer has been calibrated for 16-inch wheels and the fact that 19-inch wheels are bigger in diameter, readings will not be accurate.
7. Rims Could Get Damaged
Bigger tyres come with smaller sidewalls. The sidewalls are what protect the rims from taking a beating, and when you upsize the tyres, you are risking the rims. A decent sized pothole on the road is enough to damage the rims if you are running with bigger tyres that have small sidewalls.
8. Safety Systems Alert
Bigger than recommended tyre sizes could also hamper the vehicle's electronic safety aids such as ABS, EBD, and traction control. Compromising safety is not at all advisable.
Now looking at the above pointers, there are clearly more disadvantages than advantages of upsizing tyres. This does not mean you cannot upsize, but do not choose a size that is far away from the original size of the tyre. The safest upsizing can be an inch or two max, but more than that is trouble.
If looks are primary and you do not care about anything else, at least go with tyres that have the same load and speed rating. Speak to your tyre dealer, he will be able to guide you.