It is kind of a trend among new car owners in Pakistan to replace alloys and tyres as soon as they buy a new car. Some just change the tires but there are those who buy a new pair of alloys along with the new rubber for their shiny new car. And usually they prefer going for the bigger sizes of alloys. When you increase the size of the alloy, you have to decrease the side of the tire profile for it to fit under the fender.
For example, let’s take example of your new Toyota Corolla. It comes with a 15” alloy with a 195/65R15 Euro Star tire made by General Tyres Pakistan. You have decided to install 17” alloys on your new car, so to keep the overall same diameter of alloy wheel and tire combined, you install lower profile tires, so then can fit your car and you don’t end up with tires rubbing fender edges, or inside of the car when turning.
Decreasing the profile of the tire has its merits and demerits. Let’s start with the positives:
The major benefit is that the handling of your vehicle will improve. Since there is less cushion of rubber and air, you will only need small steering corrections while driving. You will feel more in control and if cornering hard, there will be less body roll and outward sway. If your car is on stock tires, lets say a 65 profile tire, your car will lean on the rubber more, than if you have tire profile of say 45 or even 50. There will be more bite from the tires when cornering.
Also, at high speeds, your car will feel much stable, since there is less rubber and air to ‘jiggle’ your car. You will feel planted and there will be more grip. Other than that, they look cool as well.
On the negative side, you will be losing your ride’s comfort. As said before, low profile tire means less cushion, so you will feel all the bumps and humps and potholes of the road. Even the smallest of road crack will be felt in the cabin. Also there will be road noise, and especially on high speeds.
Any weight under the shock absorber of the car is car unladen weight. So when you increase the alloy size, you are also increasing that weight. And that weight effects your car’s suspension parts far more than anything over the struts. So by increasing the unladen weight, you are putting extra stress on the suspension parts; more than what it was designed for. Your suspension bushings and parts will start to wear out far more quickly than they would on regular size alloy and tire. Also there is a major chance of you hitting a pothole and damaging those expensive alloys permanently.
So there it is, yes those shiny new bigger alloys will look good on your new Civic and they have few benefits as well, but those benefits come at the cost of your ride comfort and suspension repair bills. Considering the conditions of roads in Pakistan, it can be hard driving a car with low profile tires as your daily driver.