Sponsored Content Presented by Maxxis Tires.

No matter the make or model, track or series, all of our cars have one thing in common: They run on tires. They're the single, critical link between the car and the ground.

And with those tires come questions. Lots of questions.

Fortunately, we know someone with answers.

John Wu, an engineer by training …

Read the rest of the story

David S. Wallens
David S. Wallens Editorial Director
8/9/21 6:51 p.m.

Bumping this for the evening crew. smiley

f1carguy New Reader
8/10/21 12:53 p.m.

I learned a lot reading this article ! Thanks for the extensive answers. 

David S. Wallens
David S. Wallens Editorial Director
8/12/21 11:09 a.m.

In reply to f1carguy :

You're welcome--and any other tire questions from the floor? 

I saw this one about tire diameter vs. tire life. What other questions do we have? 

Woody (Forum Supportum)
Woody (Forum Supportum) GRM+ Memberand MegaDork
8/12/21 9:34 p.m.

Manufacturers list the proper tire pressure for original tires. 

If you upgrade to bigger wheels and lower profile tires (Plus 1 or Plus 2), would the new tires use the same pressure (weight of car is essentially the same), or do the ideal pressures now need to be adjusted?

If you need to run a different pressure, would it be higher or lower? Is there a formula to calculate this, or is it trial and error?

Patientzero Dork
8/12/21 10:44 p.m.

In reply to Woody (Forum Supportum) :

I read this a long time ago and have always assumed it to be true but it might be another good question for a tire engineer.

Tires have a maximum load rating at a certain pressure, for example 1,356lbs @ 51psi. 

From what I understand, you can use the corner weight of the car and create a ratio.  Say you have a corner weight of 800lbs you divide that by your max load.  800/1356=.589. 

Then take your ratio and multiply by the max psi.  .589x51=30.08

This would give you a starting tire pressure of 30psi.  This could all be complete bs, I read it on the internet after all but it has worked well for me for many years.

dps214 Dork
8/13/21 8:25 a.m.

Pressures probably need slight adjusting but should be pretty close. Honestly might still depend on the tire choice more than the size at that point. Depending on the sizes and conditions I'd expect slightly lower pressures due to the shorter and presumably stiffer sidewalls on the bigger wheels. I'd also hope to be able to run lower pressures to not totally screw nvh. But probably like 1-2psi I would think, which just switching tire brand/model in the same size can have that much or more variation.

JG Pasterjak
JG Pasterjak Production/Art Director
8/13/21 3:23 p.m.

As someone with way more tires than wheels frequently, I find myself mounting, dismounting and remounting the same set of tires multiple times. Does frequent mounting and remounting have any negative effect on the tire itself? Any best practices I should be suggesting to my installers when they're mounting a set of used tires?

Katie Suddard
Katie Suddard Advertising Coordinator
8/13/21 3:32 p.m.

Question for the tire engineer: If you're using a daily driver as an autocross car, do you automatically need new tires after every event or can you still daily drive on a set that aren't too torn up? 

Shaun Dork
1/30/22 5:09 p.m.

'Dicktonium'.   Thats a keeper!

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