[Main General Bulletin Board | BBFAQ | Prev by Date | Next by Date | Post Followup ] Member Login / Signup - Members see fewer ads. - Latest Member Gallery Photos More than you expect Like This Post: - Subscribe to Daily Digest for this Bulletin Board Posted by Ari [Email] (#2847) [Profile/Gallery] (more from Ari) on Mon, 5 Feb 2007 06:09:04 In Reply to: Re: Larger contact patch, TG, Mon, 5 Feb 2007 05:41:27 Alert me when someone posts in this thread: Members do not see ads below this line. - Help Keep This Site Online - Signup

As a rough approximation, the total contact patch is equal to the weight of the car divided by the tire pressure. So if you assume a police-equipped Crown Vic at 4200 lbs, and an agressive tire pressure of 35 psi in each tire, that's a total tire patch of 120 square inches (4200/35). If the weight balance were equal on all four tires, that would be about 30 sqin per tire. The actual patch is slightly larger, because due to the curve of the tire, the pressure exerted on the ground at the front and back is less.

So let's drop the tire pressure by 5 psi to 30. The total tire patch is now 140 square inches. That's better than a 16% increase in contact patch. Or an increase of 20 square inches, which is the better part of that 30 square inches of a single tire - it's like adding better than half another tire. In bad weather conditions, that's an advantage I'd take.

This is a rough calculation - there are many effects, like sidewall stiffness and tire aspect ratio. But it's a pretty good approximation.

Ain't physics swell?

posted by 192.249....

• Help me understand this, TG, Mon, 5 Feb 2007 05:08:50
  • Where in West Michigan?, No Snaab, Tue, 6 Feb 2007 18:17:51
  • This From CBS Early Show website, Ian Glenday , Mon, 5 Feb 2007 20:12:39
  • If the tire pressure was optimal to start with, ursaw, Mon, 5 Feb 2007 16:03:31
  • The idea that lowering tire pressure for snow..., dSPG89, Mon, 5 Feb 2007 07:23:12
    • Might not be so nuts..., Chaz, Mon, 5 Feb 2007 13:07:54
  • idiotic!, CrNiFe , Mon, 5 Feb 2007 07:16:10
  • Re: Help me understand this, Woody, Mon, 5 Feb 2007 06:44:32
    • Not as dumb as you think., Gene N , Mon, 5 Feb 2007 07:04:31
  • But most snow tires are narrower..., Craig, Mon, 5 Feb 2007 06:29:15
    • Re: But most snow tires are narrower..., JimBlake , Mon, 5 Feb 2007 07:55:07
  • Re: Help me understand this, JimBlake , Mon, 5 Feb 2007 05:55:46
    • Re: Help me understand this, Schu, Mon, 5 Feb 2007 06:17:37
    • Road tires aren't slicks - hopefully, Ari , Mon, 5 Feb 2007 06:15:02
      • Re: Road tires aren't slicks - hopefully, JimBlake , Mon, 5 Feb 2007 08:00:54
  • Larger contact patch, Gene N , Mon, 5 Feb 2007 05:36:47
    • Re: Larger contact patch, TG, Mon, 5 Feb 2007 05:41:27
      • More than you expect, Ari , Mon, 5 Feb 2007 06:09:04 <-- Viewing This Message
  • Bigger footprint, Dale, Mon, 5 Feb 2007 05:31:48

No Site Registration is Required to Post - Site Membership is optional (Member Features List), but helps to keep the site online
for all Saabers. If the site helps you, please consider helping the site by becoming a member.

• Prev by Date: Re: Sorry, link here..., noname, Mon, 5 Feb 2007 06:02:28
• Next by Date: Road tires aren't slicks - hopefully, Ari, Mon, 5 Feb 2007 06:15:02
• Main General Bulletin Board

StateOfNine.com

SaabClub.com

Jak Stoll Performance

M Car Covers

Ad Available

The content on this site may not be republished without permission. Copyright © 1988-2024 - The Saab Network - saabnet.com.
For usage guidelines, see the Mission & Privacy Notice.
[Contact | Site Map | Saabnet.com on Facebook | Saabnet.com on Twitter | Shop Amazon via TSN | Site Donations]

Random Saabnet.com Member Gallery Photos (Click Image)