Correct tire pressure ensures proper inflation, safe driving, and a longer lifespan of tires. Additionally, under-inflated tires generate excessively high temperatures that can weaken them to the point of failure. So, proper tire pressure maintenance is crucial.
Today, I’ll discuss Tire Pressure Conversion Charts – bar to psi and psi to bar and other pressure units.
Common tire pressure measurements are bar, PSI, and kPa. You can get the tire pressure in PSI by multiplying the Bar value by 14.5 (1 Bar = 14.5 PSI). Similarly, to convert PSI to Bar, divide the value by 14.5. Likewise, to convert Bar to kPa and PSI to kPa, multiply by 100 and 6.8947, respectively.
Alright, let’s get to the pressure conversion and its importance in detail.
Tire Pressure Conversion: Commonly Used Measurements
Image Source: Shifting Gears
The commonly used tire pressure measurements are PSI, Bar, and kPa. You can easily convert these three with simple formulas. Follow the conversion chart below.
Tire Pressure Conversion Chart
| Pressure Conversion Chart | |||
| Convert From | Convert To | Multiply By | Divide By |
| Bar | PSI | 14.5 | – |
| PSI | Bar | – | 14.5 |
| Bar | kPa | 100 | – |
| kPa | Bar | – | 100 |
| PSI | kPa | 6.8947 | – |
| kPa | PSI | – | 6.8947 |
So, the table shows that to convert Barr to PSI you have to multiply the value by 14.50 (1 Bar = 14.50 PSI). Similarly, for PSI to Bar conversion, you must divide the value by 14.50. For example, if the tire pressure is 32 PSI, then 32/14.5 equals 2.20 Bar.
You can follow the chart to convert other pressure units, such as from Bar to kPa and PSI to kPa and vice versa. Now, check out the below table for ideal tire pressure for different vehicle categories. The tire pressure is given in all three measurements.
Ideal Tire Pressure for Different Vehicle
| Vehicle Categories | Types | PSI | Bar | kPa |
| Cars | Small Cars | 25-32 | 1.72-2.21 | 172.41-220.69 |
| Medium/Large Cars | 32-35 | 2.21-2.41 | 22.69-241.38 | |
| Motorcycles | ||||
| Bikes | Road Tires | 80-130 | 5.52-8.97 | 551.72-896.55 |
| Hybrid Tires | 40-70 | 2.76-4.83 | 275.86-482.76 | |
| Mountain Bikes | Tubes Tires | 30(Front)-30(Back) | 2.07 | 206.90 |
| Tubeless Tires | 22(Front)-24(Back) | 1.52-1.66 | 151.72-165.52 | |
| SUVs | – | 32-35 | 2.21-2.41 | 22.69-241.38 |
| Truck | – | 55(Front)-80(Back) | 3.79-5.52 | 379.31-551.72 |
| Semi-truck | 75-80 | 5.17-5.52 | 517.24-551.72 |
Note: Tire pressure may vary depending on the below factors:
- Tire pressure can vary on front engine and back engine drive layout.
- Vehicle brand, load, tire types, and weight influence the tire pressure.
- For mountain bikes, tire pressure is determined by specific tire types and skills.
What Is Normal Tire Pressure?
Normal tire pressure means your vehicle’s tires have the proper pressure required for a better driving experience. The tire depends on several factors and different types of vehicles. Let’s check out the ideal idle tire pressure for cars, bikes, trucks, etc.
What’s the Ideal Tire Pressure for Cars?
The ideal tire pressure for a car ranges between 32-25 PSI or 2.21-2.41 Bar or 22.69-241.38 Kilopascal. Always follow the owner’s manual or the tire pressure information sticker on the driver’s seat when adjusting tire pressure.
What’s the Ideal Tire Pressure for Motorcycles?
The ideal tire pressure for street motorcycles is up to 28 PSI in the front tires and 40 PSI in the rear tires. Remember that this refers to average values; the tire pressure varies depending on tire types, your driving style, and manufacturers.
What’s the Ideal Tire Pressure for Bikes?
The ideal tire pressure for road tires ranges between 80 to 130 PSI for bikes. And, for the hybrid tires, the range is between 40-70 PSI. The tire pressure requirement may vary depending on driving skills, engine power, the bike’s weight, and the manufacturer.
Additionally, when it comes to mountain bikes with tubed tires, the pressure should be about 30 PSI both front and rear and 22PSI (front)-24PSI (back). Follow your owner’s handbook for the exact tire pressure recommended for your mountain bike.
What’s the Ideal Tire Pressure for Trucks?
The ideal tire pressure for a heavy vehicle like a truck is 55 in the front and 80 in the back. The variation of the tire pressure helps to balance and distribute the excess weight for better handling. It also ensures better braking and cornering at top speed.
What’s the Ideal Tire Pressure for SUVs?
The ideal tire pressure for SUVs must be 32-35 PSI. SUVs typically need better handling, cornering, tire grip, and braking. Proper tire pressure is crucial to ensure top-notch driving performance and emergency braking situations.
Should All Your Tires Be The Same PSI?
Yes, to maintain vehicle weight balance and improve driving performance, all four tires should have the same tire pressure. You can find the recommended tire pressure in the owner’s manual. The tire pressure chart sticker is also located on the driver’s door.
Image Source: Volvo cars
What Should Front And Back Tire Pressure Be?
Front-wheel-drive (engine in the front) cars have higher front tire pressure than rear tires. It compensates for the extra weight of the engine and transmission. In contrast, rear-wheel-drive cars have lower front tire pressure for better handling.
How To Measure Tire Pressure?
There are many ways to measure tire pressure. You can get help from the mechanics or service centers to measure tire pressure. You can also measure tire pressures at home. Below are the steps and tools required to measure the tire pressure properly.
Tools Required
- Tire Inflator
- Digital Tire Pressure Gauge or Mechanical Gauge.
Step 1: Ensure the Tires are Cool
The first and most important step is to measure the tire pressure when the tires are cool. Tires are usually heated after diving due to friction. Tire pressure will change by one psi for every ten-degree change in temperature.
Hence, you should measure the tire pressure when the tire has properly cooled after a drive. Try measuring the temperature at least after one night of driving.
Step 2: Use Tire Pressure Gauge
Now unscrew the tire valve stem to measure the tire pressure using the pressure gauge. Take a pen and paper, or simply use your phone to note the tire pressure readings. Crosscheck the values with the recommended value by the manufacturer.
There are two types of gauges available: Mechanical and Digital. If you’re confused or don’t know how to use the Tire Pressure Gauge, consider watching this simple video.
Checking tire pressure with a digital gauge (Using digital gauge)
How to Check Tire Pressure – Checking Tire Pressure (Using mechanical gauge)
Disclaimer: Depending on the accuracy of the gauge, tire pressure readings may vary. So, to ensure proper tire pressure reading, I would recommend the digital gauge over the mechanical one. Comparatively, the digital gauge offers better functionality.
Step 3: Fill the Tires With Recommended PSI
Lastly, find the tire pressure placard on the driver seat or go through the owner’s handbook for the recommended tire pressure. Now, fill the tires with the recommended tire pressure using the tire inflator automatic compressor.
What Is Meant By Tire Pressure?
Image Source: Continental Tires
The tire pressure indicates the total atmospheric pressure inside the tire. The PSI (pounds per square inch) is used in the U.S., while the Kilopascal (kPa) is used in Europe. Bar (atmospheric pressure) is widely used in Europe and other areas.
How Do I Know What Tire Pressure I Need?
Always follow the owner’s handbook to get the recommended tire pressure for your vehicle. Pressure depends on factors like tire type, driving style, speed, etc. So, make sure you follow what’s recommended for your vehicle.
What Happens If Tire Pressure Is High?
High tire pressure can distort the tire’s shape, resulting in decreased traction and increased tearing. As a result, it affects the overall driving experience, like handling, cornering, braking, and ride comfort.
What Happens If Tire Pressure Is Low?
Low-pressure tires wear off the tires faster and significantly affect driving performance. The tires will be less stable due to reduced grip and traction. Furthermore, low tire pressure results in sloppy tires and poor braking performance.
FAQs
How Tire Pressure Affects Grip?
The grip is the contact patch size between the road and the tires. Proper pressure results in a larger contact patch, which means better grip. Low tire pressure causes a smaller contact patch, which leads to a reduced grip and an inability to absorb impact.
How Tire Pressure Affects Driving?
Proper tire pressure in all vehicle tires ensures even distribution of the vehicle’s weight. It also ensures tires have good road traction. Additionally, proper tire pressure contributes to smooth driving, better cornering, and emergency braking.
How Temperature Affects Tire Inflation?
For every ten degrees rise or fall in temperature, tire pressure changes by 1-2 PSI. Summer heat increases tire pressure, while winter condenses it. Hence, during winter, tires should be inflated up to 3 PSI higher than summer tires.
The Bottom Line
That was all about tire Pressure Conversion Charts – bar to psi and psi to bar and other pressure units.
Hopefully, you have learned how to calculate, measure, and adjust the tire pressure for your desired vehicle. Best of luck, until next time.