Many car enthusiasts are curious to see if small wheels can speed up cars. As an engineer, lemme explain everything you need to know.
Putting smaller wheels on a car doesn’t necessarily make the car faster as it mainly depends on Engine torque, Gear ratio, Final drive ratio, and wheel radius. Thus, at some engine speeds, the car may accelerate faster with smaller wheels, while some engine speeds are beneficial for regular wheels.
Moreover, using smaller wheels on a car has both pros and cons. We’re gonna look into every aspect of this topic in detail.
Table of Contents
Are cars with small wheels fast?
Technically speaking, it seems YES. Practically, it depends.
I invite you to read this whole article carefully, you won’t regret it. No matter what your education level is, everything is simply explained.
Let’s start off with understanding the simple fundamentals of wheel dynamics. There should be a torque through its axis to get the wheels to rotate.
Here is the equation for wheel torque…
If we assume the wheel torque as a constant, it seems a low wheel radius tends to produce a higher Wheel tangential force, which means, according to this equation, smaller car wheels tend to go fast.
This is because the Wheel tangential force of the wheel is essentially the force that propels the vehicle forward.
If you do not understand, think like this. Let’s simply say Wheel torque is 1000 and wheel radius is 10, then you have a 100 of Wheel tangential force.
Assuming the wheel torque is constant, if the wheel radius becomes 5, then the Wheel tangential force will be 200. I think you got this.
But, this is not the case…
Can we actually assume the Wheel torque as a constant variable when you drive the car?
NO!!!! LET ME EXPLAIN…..
But, prior to that, we have to make some assumptions. (I’m not gonna explain and prove everything because it is boring for most readers.)
- The vehicle is driving in a stright line.
- No slip in the cluch.
- No slip in the torque converter.
- The car is a two-wheel drive car. (RWD or FWD)
The Wheel torque MAINLY depends on the following.
- Engine torque.
- Gear ratio.
- Final drive ratio.
So, here are the equations…
If you cannot understand the above equation, don’t even worry about it.
Essentially you need to realize that putting smaller tires would help to accelerate the car in some gears and in specific speeds.
So, how do we understand the relationship between vehicle speed and wheel size?
To understand the relationship between the vehicle speed and the wheel size, we need to drow a graph showing the car speed against engine speed in each gear with both the regular wheels and smaller wheels.
Then you will realize that there are certain engine speeds where the car with smaller wheels accelerate fast while in some engine speeds the car with regular large wheels accelerate fast.Mr. Madhusanka (Engineer)
I hope you go with the idea. Please lemme know in the comment section down below if you got any problems with this.
Do cars with bigger wheels go faster?
As we discussed so far, a car with bigger wheels must go faster at some engine speeds.
Because as I mentioned earlier, the vehicle speed depends on many real-world variables, including Engine torque, Gear ratio, Final drive ratio.
Suggested Reading: Why Do Modern Tires Not Use Inner Tubes?
Advantages of installing small wheels on a car.
Lemme explain to you several disadvantages of installing small wheels on your car.
- Smaller wheels can improve the traction.
- Provide better handling.
- Less sidewall roll of the wheels when taking sharp turns.
- Transmit more torque to the ground in certain speeds.
- Boosts the aesthetic of your car.
- Improve the stability at high speeds.
- Provide high control over the vehicle on wet surfaces.
- Tend to offer better mileage.
- Give high acceleration to up to specific speeds. (This speed depends, so it can be anywhere between 30-60 kmph or more)
Disadvantages of installing small wheels on a car.
Here are some of the disadvantages of putting small wheels on your car.
- You will have to re-calibrate sensors and speedometers, odometer.
- You may have to so many modifications including lowering springs, brackets, shocks, arms, stabilizing bars, etc.
- So, this is costly process.
- Transmission shifting issues.
- Perhaps, you have to deal with issues like with proper wheel alighment angles.
- You may experiance issues with Advanced Driver Assistance Safety system.
- Since smaller wheels cause car to rid lower, resulting in vehicle to collidate with objects, scraping the bottom. You may face it difficult to pass things like roadway debris, speed bumps.
- Wheels tend to wear out dramitcally faster as smaller wheels rotate faster.
- May lower the vehicle performance indirectly.
Things to be aware of.
I hope you now have a good solid understanding of what happens when someone puts small wheels in a car.
But that’s not sufficient. You need to keep in mind several crucial things as a vehicle enthusiast.
Hear me out.
Follow the manufacture: Don’t even think of changing your wheels to smaller wheels in a case where your car manufacture hasn’t specified it as a modification option. Remember, it affects your lovely car in many ways.
Aesthetic is not everything: Fitting your car with smaller wheels for aesthetic purposes isn’t suitable as it may affect the car’s performance.
Seek professional advice: If you’re unsure what to do, please consider seeking professionals’ advice before making any changes. I’m pretty sure that this will definitely save your valuable time and money.
User manual: Please consider reading your vehicle’s user manual. This will educate you with much valuable information about your vehicle.
When driving on winding roads: Since a car with smaller wheels tends to accelerate quickly up to 30-60kmph from lower speeds, you will have to change gear quite often when driving on winding roads. It’s really difficult.
The acceleration insignificant: If you decide to put smaller wheels on your car hoping to drive faster, just be aware that it’s really unnecessary. Because the time difference when you accelerate 0-60 with regular wheels and smaller wheels could be one second or even lower. So, ask yourself, is that something you wanna spend time and money on? In fact, this can alter your vehicle’s performance. However, this can be a huge factor if you’re a motor racing guy. But, I guess you’re a regular person like me. So, think wisely.
Who doesn’t love to go fast in their own car? So, many car enthusiasts think that they can go faster if they have small wheels fitted to their cars. Unfortunately and fortunately, it isn’t true as this speed depends on factors such as Engine torque, Gear ratio, Final drive ratio, Wheel radius, and even minor factors like friction between the wheels and the road, wind resistance, heat, etc. So, in this article, we’ve discussed a lot of crucial things that you, as a car enthusiast, should know. Hope you found this helpful.