Smaller Tires (Increase Speed, Improve MPG, Speedometer)


When you want to change your car’s tires, you need to ensure that you get the correct size. There is a debate about smaller tires versus bigger tires and their effect on the car’s speed. One of the questions that most people have is whether smaller tires increase the speed of your car.

So, do smaller tires increase speed? Smaller tires can increase the speed of a car because they accelerate faster than bigger tires. Smaller tires increase speed because of the higher force applied by the axle on the lug nuts to compensate for the shorter radius. The higher amount of force will make the smaller tires spin faster, covering a longer distance within a short time. However, before installing smaller tires on your car, ensure they are within the size recommended by your car’s manufacturer.

Many drivers want their cars to perform at their best and will change or modify a certain aspect of their car to increase speed. You may have heard the discussion on how the size of your car’s tires can affect its speed. If you want to use smaller tires, you might be wondering if they can increase your car’s speed.

Smaller tires do increase the speed of a car because of their quick acceleration. When you install smaller tires on a car that uses bigger tires, the car will apply higher force to compensate for the shorter radius.

The higher force will make the tires spin faster, covering a longer distance within a short time, hence making your car faster. However, other things will make the smaller tires increase your car’s speed, such as grip and correct tire pressure. It is important to note that you should only use smaller tires that are within the recommended tire size by the car’s manufacturer.

To understand why smaller tires, increase your car’s speed first, you need to know how the wheel works. The wheels are attached to your car on an axle. When you turn on the engine and press on the accelerator, the axel produces a torque on the axis of the wheels, which makes them spin, moving your car forward or backward.

The force applied on bigger tires to make them spin is low compared to the force applied when the car has smaller tires. The torque usually remains the same whether you use bigger or smaller tires.

However, it is not guaranteed that the smaller tires will increase speed because other factors can cause your car to be slow even with smaller tires. One of the factors is the tire’s tread; if the tires have low tread, your car will lose traction, making it hard to accelerate.

If you install worn-out smaller tires on your car, they will not have a huge impact on your car’s speed. Therefore, if you install smaller cars to increase speed, ensure that they have high tread. Tires with high treads have better grip and hence will not slip when you accelerate.

Incorrect tire pressure can also affect your car’s speed and performance. If you use smaller tires and they are underinflated or overinflated, your car might have difficulty accelerating. Most cars need a tire pressure to be between 30 to 35 PSI.

When you install smaller tires with low tire pressure on your car, the car will use more energy to move. Your engine will work even harder to ensure the car maintains the same speed, increasing your car’s fuel consumption. Using smaller tires with low pressure could affect your car’s stability and handling. If you drive at high speeds with low pressure, it could be harder to control the car, and you might end up causing an accident.

In addition to increasing your car’s speed, the smaller tire offers better handling. Smaller tires also improve your car’s towing power compared to the larger tires because they transfer more torque to the ground. You can navigate through sharp corners at relatively high speeds without losing control.

Smaller tires also improve your car’s look by lowering your car closer to the road. If you want to install smaller cars on your car, ensure that you follow your car manufacturer’s instructions. You should also use a professional mechanic or tire expert to switch from large tires to small tires.

One of the most important parts of your vehicle is the tires. When they get damaged, you need to replace the damaged tires with the correct size to ensure your car functions properly.

Does Changing Tire Size Affect Speedometer

The speedometer is one of the most important features in a car because it tells the driver how fast they are going. The speedometer needs to give an accurate reading, and if it gives a false reading, you might cause an accident or get in trouble with the traffic police for over speeding. If you have decided to change your car’s tire size, you might wonder if the changes can affect your speedometer.

Changing your tire size does affect the accuracy of the speedometer. The speedometer reading will be slower than your actual speed when you increase the tire size. When you install smaller tires, the speedometer will read a faster speed than your actual speed. Changing the tire height will also affect your speedometer’s accuracy.

Your speedometer showing inaccurate speeds can be dangerous and cause you legal troubles. To avoid getting inaccurate speed readings from your speedometer, ensure you install the correct tire size on your car. 

The speedometer shows speed reading by how fast your tires are rotating. A bigger tire rotates much slower than a smaller tire; hence, if your car was using smaller tires and installing bigger tires, the speedometer reading will be inaccurate.

The reading on the speedometer will be slower than the car’s actual speed, which can be dangerous for you and your passengers. Smaller tires have a small diameter and rotate faster, causing the speedometer to show a higher speed than your car’s actual speed.

After changing your car’s tires, you can check the speedometer’s accuracy by doing a road test. Most freeways have mile markers that show the length of each mile you are traveling. Drive your car to a freeway and set your cruise control at 60 MPH.

You should have a passenger with a stopwatch start the stopwatch immediately when you pass the mile marker. If the road is clear, it should take 60 seconds to reach the next mile marker. Repeat the test three or four times, and if your average time is off by three seconds, your speedometer could be giving inaccurate readings.

After you have changed your car’s tire size, you can recalibrate the speedometer to ensure that it gives accurate readings. If your car has a mechanical speedometer, open the hood of your car and locate the transmission.

Proceed to unscrew the speedometer cable from the car’s transmission. Remove the plate and expose the two gears, the driven gear and the drive gear. Count the number of teeth on the drive gear and write down the number.

Measure one of your car’s wheels to get the diameter. Use the diameter to divide 20,168 to get the tire’s RPM. Multiply the RPM by the number of teeth of the drive gear. Multiply the axle’s ratio by the value obtained by multiplying the RPM by the number of teeth.

Divide the value by 1,001, and the resulting number is the number of driven gear teeth needed. By the driven gear teeth with the correct number of teeth, remove the old, driven gear and install the new one.

If your car is using an electronic speedometer, first read the owner’s manual to determine the distance of the test drive. Press and hold the calibration button on the speedometer, start your car and release the button.

Press the button again and drive the distance indicated in the owner’s manual. Contact the car’s manufacturer if you cannot find the distance in the owner’s manual. Press the recalibration button again after driving the required distance. The speedometer will recalibrate itself and will start giving accurate readings according to the new tire size. 

Does Smaller Wheels Improve MPG?

MPG or miles per gallon is a way of measuring how far your car can travel with every gallon in the fuel tank. With gas prices going up, most people are looking for ways to use less gas to travel longer. Tires can affect your car’s performance, and you might be wondering if your car will manage fuel efficiency if you use smaller wheels.

Smaller wheels do improve MPG because they offer less resistance, hence the engine does not have to work harder to maintain speed. Bigger wheels cover more ground and have slow rotation compared to smaller wheels. When you install bigger wheels on your car, the tires will have more surface area, increasing friction between the tire and the tarmac.

The high friction will result in higher rolling resistance than the smaller tires. Your car’s engine will have to produce more energy to counter the excess friction and maintain cruising speed, increasing fuel consumption.

However, you should only install the correct wheel size on your car as recommended by the manufacturer. Installing smaller wheels could lead to problems like inaccurate speed reading, causing the anti-lock brakes to malfunction and trip your engine light.

When changing tires, you have to select compatible tires that will make your car perform optimally. You need to select a tire size that will offer less resistance. The more weight and resistance the tires add to your car, the harder the engine will work to move the car. Therefore, do not go for the biggest ones you can afford when selecting car wheels.

Big tires have more resistance and add extra weight to your car. The more resistance your car has, the more fuel it will burn. You need to buy the smallest wheels that you can install on your car without affecting its overall performance. You may have to refer to the owner’s manual or call the car’s manufacturer to know which is the smallest size you can have for your car.

To improve your car’s fuel consumption, the first step is selecting smaller tires and ensuring that they are the right pair of tires. The next step is to ensure the tires have the recommended tire pressure. Most cars use 30 or 35 PSI, but you should read the owner’s manual to ensure you use the manufacturer’s tire pressure recommendation.

You should also check the tire pressure regularly to ensure all tires have the correct PSI. If you drive your car with smaller tires, but they have low pressure, the tires will increase the car’s resistance leading to the engine burning more fuel.

Another thing you should do to improve your car’s fuel consumption is to maintain your car. Misalignment can cause your tires to wear out more quickly. Misaligned wheels can cause your cars to consume more fuel.

When installing new tires on your car, you must ensure they are properly balanced and rotated according to the owner’s manual. To know if your car needs a tire alignment, check the tires for uneven tread wear, if the vehicle is pulling to the left or right, if your steering wheel is off-center when driving strain and if the steering wheel is vibrating.

Changing to smaller tire sizes will improve your car’s fuel consumption, but it also has disadvantages. When changing to smaller tires, you might be required to lower the kit or springs, arm brackets, stabilizing bars, and shacks. You will also need to change the driven gear if your car uses a mechanical speedometer.

These changes could affect your car’s sensors, which are not cheap. Another problem with changing to smaller tires is inaccurate speedometer and odometer readings which can be dangerous if not corrected. Your car might also scrap on the ground or get stuck on speed bumps which could damage the underside of your car.

Wrap Up

If you are considering putting smaller tires on your car to improve its fuel consumption and increase speed, you must check with your owner’s manual for the manufacturer’s recommendations. Do not install tires, whether big or small, that are not recommended by the manufacturer.

After installing the smaller tires, you should also ensure your car is well maintained to achieve the desired results. The smaller tires should have enough tread, be well aligned and balanced, and have the recommended tire pressure at all times. When you get the small-size tires recommended for your car, you can have a professional mechanic or tire expert install them.

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