Are Your Tires Properly Inflated?

Discount Tire

Active Member
For people who need to be on the roads, making sure your tires are properly inflated will not only save you money at the pump, allow the tires to perform properly in the rain, but will also aid in proper wear.

  • Fuel Efficiency - For every 1 PSI drop in tire pressure the US Department of Energy estimates a loss of .4% in fuel efficiency. Although this may not seem like much, over time it can add up.

  • Wet Performance – When a tire is under inflated the contact patch won't be evenly distributed on the road surface. This restricts the treads ability to displace water properly and can cause hydroplaning.

  • Wear – Improper tire inflation can cause irregular treadwear and potentially damage, resulting in reduced life and early replacement.


Want to learn more? Follow the link below to discover tire pressure related topics and how inflation pressure can change under different environments.


EDUtire-pressure_tire-pressure_hero.jpg



How can Discount Tire help?

We want to make sure your tires are safe! In that spirit we offer FREE air checks and tire inspections. This can all be done while you remain comfortably in your vehicle. Right now, most of our store locations are open, and we have taken extra precautions to keep you and our staff safe.

If you are unable to make it down to a store, please feel free to reach out to us through Private Message if you have any questions - we're here to help!
 

Ddays

Hooked
What is your recommendation regarding aftermarket tires? I think most people on this site have used the chalk method to figure treadware across the whole tread-width of the tire to find an acceptable ride and handling characteristics.
Also, what about the guys running 37 & 40" tires with E rated sidewalls?
 

Discount Tire

Active Member
Thank you for your question, Ddays!

Pressure tends to be a personal preference, however, tires are pneumatic so one needs to be aware of the minimal safe "cold" inflation pressure.

When setting air pressure we follow industry standard by setting the replacement tires to the PSI that will match the factory tires load rating. More specifically, we look at the factory tire's load index/construction and the factory recommended cold air pressure (placard located on the door jam), then plug these two numbers into a Load Inflation Chart and the chart indicates how much load the factory tire carries at the factory recommended pressure. We then look up the new tires load index/construction on the chart and go across to the same weight the factory tire carries and check the corresponding PSI to carry this weight.

As an example using a 2020 Jeep Wrangler Unlimited Rubicon, it comes factory with LT285/7R-17 116 LR-C1 tires. The load rating is 116 which makes it 2,199 pounds at placard pressure of 37 PSI. If the new tire was a Cooper STT Pro 40x13.50R-17 121 LR-C2, checking the load inflation chart, the corresponding load carrying capacity to meet that weight, the tire needs to be filled to 25 PSI.

Keep in mind this is the minimum cold inflation pressure, you can adjust the pressure as you wish upward to your liking as long as you don’t exceed the maximum pressure listed on the sidewall of the tire.
 
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wjtstudios

Hooked
Thank you for your question

As you noted, pressure tends to be a personal preference, however, tires are pneumatic so you need to be aware of the minimal safe "cold" inflation pressure.
When setting air pressure we set the tires to the PSI that will match the new tire to the factory recommended tires load rating. We look at the factory tire's load index and the factory recommended cold air pressure (placard located on the door jam). Plug these two numbers into a Load Inflation Chart and the chart indicates how much load the factory tire carries at the factory recommended pressure. We then look up the new tires Load Index on the chart and go across to the same weight the factory tire carries and check the corresponding PSI to carry this weight.

As an example using a 2020 Jeep Wrangler Unlimited, it comes stock with a BFG 285/7R-17 116 LR-C1 tire. The load rating is 116 which makes it 2199 pounds at placard pressure of 37 PSI. If the new tire was a Cooper STT Pro 40x13.50R-17 121 LR-C2, checking the load inflation chart, the corresponding load carrying capacity is 2680 pounds, the air pressure to achieve this weight would be 25 PSI.

Keep in mind this is the minimum cold inflation pressure you can adjust the pressure as you wish upward to your liking as long as you don’t exceed the maximum pressure listed on the sidewall of the tire.

That is very helpful and informative. Thank you!


2015 JKUR AEV JK350
1985 CJ8 Scrambler
 

Primo82

Caught the Bug
Thank you for your question

As you noted, pressure tends to be a personal preference, however, tires are pneumatic so you need to be aware of the minimal safe "cold" inflation pressure.
When setting air pressure we set the tires to the PSI that will match the new tire to the factory recommended tires load rating. We look at the factory tire's load index and the factory recommended cold air pressure (placard located on the door jam). Plug these two numbers into a Load Inflation Chart and the chart indicates how much load the factory tire carries at the factory recommended pressure. We then look up the new tires Load Index on the chart and go across to the same weight the factory tire carries and check the corresponding PSI to carry this weight.

As an example using a 2020 Jeep Wrangler Unlimited, it comes stock with a BFG 285/7R-17 116 LR-C1 tire. The load rating is 116 which makes it 2199 pounds at placard pressure of 37 PSI. If the new tire was a Cooper STT Pro 40x13.50R-17 121 LR-C2, checking the load inflation chart, the corresponding load carrying capacity is 2680 pounds, the air pressure to achieve this weight would be 25 PSI.

Keep in mind this is the minimum cold inflation pressure you can adjust the pressure as you wish upward to your liking as long as you don’t exceed the maximum pressure listed on the sidewall of the tire.


Great Info! Is the Load Inflation Chart readily available by any chance? I'm running stock now, but in the future this will be very helpful!
 

Bierpower

Hooked
That's all kinds of cool info right there.

So why is it your stores inflate to the door plate pressure instead of what the individual vehicle actually needs?



--
Build Thread - Adventures of Fiona - https://wayalife.com/showthread.php?t=47407
I'm sure this has a lot to do with liability. What's listed on the door is known to be a safe operating pressure. It's much simpler to tell all the techs to check the door than it is to give them a chart and make them look up data to find what that specific vehicle and tire should have. It probably plays into timely service as well.

Sent from my Pixel 2 XL using WAYALIFE mobile app
 

Ddays

Hooked
Thank you for your question, Ddays!

Pressure tends to be a personal preference, however, tires are pneumatic so one needs to be aware of the minimal safe "cold" inflation pressure.

When setting air pressure we follow industry standard by setting the replacement tires to the PSI that will match the factory tires load rating. More specifically, we look at the factory tire's load index/construction and the factory recommended cold air pressure (placard located on the door jam), then plug these two numbers into a Load Inflation Chart and the chart indicates how much load the factory tire carries at the factory recommended pressure. We then look up the new tires load index/construction on the chart and go across to the same weight the factory tire carries and check the corresponding PSI to carry this weight.

As an example using a 2020 Jeep Wrangler Unlimited Rubicon, it comes factory with LT285/7R-17 116 LR-C1 tires. The load rating is 116 which makes it 2,199 pounds at placard pressure of 37 PSI. If the new tire was a Cooper STT Pro 40x13.50R-17 121 LR-C2, checking the load inflation chart, the corresponding load carrying capacity to meet that weight, the tire needs to be filled to 25 PSI.

Keep in mind this is the minimum cold inflation pressure, you can adjust the pressure as you wish upward to your liking as long as you don’t exceed the maximum pressure listed on the sidewall of the tire.


Awesome - thanks for taking the time to explain.

So it actually turns out that the chalk method is fairly reliable for us that are math challenged. :thinking:
 

Discount Tire

Active Member
Thank you all for your comments, we're glad we could be of assistance.

Inflation tables are not readily available online but we're happy to look up any pressure information - just shoot us a PM.

Your local Discount Tire store can set the tires to a specific pressure if you ask them as long as it meets the minimum required pressure.
 
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