Go Back   EcoModder Forum > Forum News & Feedback
Register Now
 Register Now
 

Reply  Post New Thread
 
LinkBack Thread Tools
Old 08-30-2010, 05:04 PM   #41 (permalink)
Master EcoModder
 
euromodder's Avatar
 
Join Date: Jul 2010
Location: Belgium
Posts: 4,683

The SCUD - '15 Fiat Scudo L2
Thanks: 178
Thanked 651 Times in 516 Posts
Quote:
the increased pressure will increase the tire radius
The flat side on the grond will be lifted up, making the tyre stand a bit taller.

But I seriously doubt a few more psi will stretch the circumference (say 2m) of the tyre to any noticeable extent - which ultimately is what is in contact with the road, no matter at what psi.

1 revolution of the axle will always get you 2m further, i.e. 1 revolution of the tyre.

__________________
Strayed to the Dark Diesel Side


Last edited by euromodder; 08-30-2010 at 05:09 PM..
  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 08-30-2010, 05:17 PM   #42 (permalink)
Legend in my own mind
 
trikkonceptz's Avatar
 
Join Date: Apr 2008
Location: Homestead, Fl.
Posts: 927

Evil Pumpkin - '08 Scion xD RS 1.0 #1633
90 day: 35.45 mpg (US)

Silent Silver Killer - '10 Honda Insight EX
90 day: 51.5 mpg (US)
Thanks: 2
Thanked 14 Times in 13 Posts
Quote:
Originally Posted by Weather Spotter View Post
What car what that with?

I also added your data to the wiki:
Increase tire pressure to max sidewall - EcoModder

It was a 2004 Pontiac Vibe, Automatic.
__________________
Thx NoCO2; "The biggest FE mod you can make is to adjust the nut behind the wheel"

I am a precisional instrument of speed and aeromatics
If your knees bent in the opposite direction......what would a chair look like???





  Reply With Quote
Old 08-30-2010, 05:39 PM   #43 (permalink)
Hypermiler
 
PaleMelanesian's Avatar
 
Join Date: Dec 2007
Location: Texas
Posts: 2,321

PaleCivic (retired) - '96 Honda Civic DX Sedan
90 day: 69.2 mpg (US)

PaleFit - '09 Honda Fit Sport
Team Honda
Wagons
90 day: 44.06 mpg (US)
Thanks: 611
Thanked 430 Times in 282 Posts
I can only report that higher pressures greatly increase the rolling distance of my car. I don't know how much mpg improvement that gives, but it is a positive. Better rolling = longer glides with fewer and shorter pulses to maintain speed.
__________________



11-mile commute: 100 mpg - - - Tank: 90.2 mpg / 1191 miles
  Reply With Quote
Old 08-30-2010, 08:02 PM   #44 (permalink)
Master EcoModder
 
Join Date: Sep 2009
Posts: 5,927
Thanks: 877
Thanked 2,023 Times in 1,304 Posts
I think he meant decrease rolling resistance.

regards
Mech
  Reply With Quote
Old 08-31-2010, 12:48 AM   #45 (permalink)
Lead-footed Econewbie
 
Join Date: Apr 2009
Location: Wellington, New Zealand
Posts: 52

Ceffy - '97 Nissan Cefiro 25 excimo
90 day: 25.21 mpg (US)

Demio - '07 Mazda Demio Sport
90 day: 30.99 mpg (US)
Thanks: 4
Thanked 5 Times in 2 Posts
Quote:
Originally Posted by Old Mechanic View Post
24,000 miles rotated once.

Contact patch size is reduced with higher pressures which places more weight per square inch on each square inch of contact patch.
Coefficient of friction is the single biggest factor in traction here. Reducing the size of the contact patch linearly increases the contact pressure by area, you end up with only a slight reduction in available grip.

Only, going above max sidewall may deform the tire, you start to lose traction.

With the occasional exception, running up to max sidewall pressure should not compromise the wear and performance of any decent tire. It should be designed not to lose it's contact patch shape at the rated sidewall pressure.

I have front wheel drive, the rear tires don't wear perceptably, but the front ones wear on the outside edge quite strongly (power steering, front wheel drive and macpherson strut suspension). Running my tyres at max sidewall of 41psi I can't get the tires to wear unevenly - the they are still wearing at the outside edges faster than the centre.

I can confirm that pumped up tires will most certainly loose traction much faster on rough, loose or soft surfaces. Had a scare or two

If your driving on sandy, muddy, gravelly surfaces you want to back of the pressure a bit.
  Reply With Quote
Old 08-31-2010, 02:53 PM   #46 (permalink)
EcoModding Lurker
 
Join Date: Jul 2010
Location: Ontario
Posts: 3
Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by gasstingy View Post
..The Ford Explorer fiasco was using Firestone tires that the tread peeled off of. Firestone tried to claim they were underinflated. Underinflation is a serious safety issue, but I don't agree that overinflation is a problem.
The original reccomended tire pressure for those explorers was actually only 24psi, when the replacement tires were installed in the recall (Goodyear Wrangler RTS), Ford issued a new door jamb sticker to accompany them which raised the reccomended tire pressure to 30-35psi (I can't remember for sure what the new pressure was).

Quote:
Originally Posted by Frank Lee View Post
F150 came with OEM Firestones- best dang tires it ever had. I hunted for exact replacements but there were none to be had
Some tires that come OEM on vehicles are only issued to the OEM as they are purchased specially. Typically if that is the case, you can find the same tires under a different name.
  Reply With Quote
Old 08-31-2010, 05:10 PM   #47 (permalink)
Wiki Mod
 
Weather Spotter's Avatar
 
Join Date: Nov 2009
Location: Midland MI, USA
Posts: 2,042

Max - '14 Ford C-Max SEL
Thanks: 228
Thanked 304 Times in 210 Posts
I updated the wiki to reflect the change in wording.

New wording:
Reduces rolling resistance which decreases the amount of power your car needs to move.

There are mixed anecdotal reports about improvements in other properties (steering response, wet traction, and tire wear). Some folks report improvements and some report degradations.
__________________
  Reply With Quote
Old 03-04-2011, 12:11 AM   #48 (permalink)
EcoModding Lurker
 
ktaylor's Avatar
 
Join Date: Mar 2011
Location: Vancouver
Posts: 32

Burgandy B*tch - '99 Buick Regal LS
90 day: 27.78 mpg (US)

Faze - '86 Yamaha FZ 750
90 day: 36.83 mpg (US)
Thanks: 13
Thanked 2 Times in 2 Posts
I have a question, what is the limit to inflating tires. My Nokian WR's have a max sidewall of 81 psi and are currently inflated 50/45 F/B. I don't feel too comfortable with going any higher but I keep reading in the forum "just bring it to max sidewall." Also, were do I buy a good pressure gauge? Like Home-depot, or Canadian Tire?
  Reply With Quote
Old 03-04-2011, 03:32 AM   #49 (permalink)
Master EcoModder
 
euromodder's Avatar
 
Join Date: Jul 2010
Location: Belgium
Posts: 4,683

The SCUD - '15 Fiat Scudo L2
Thanks: 178
Thanked 651 Times in 516 Posts
Quote:
Originally Posted by ktaylor View Post
I have a question, what is the limit to inflating tires. My Nokian WR's have a max sidewall of 81 psi and are currently inflated 50/45 F/B. I don't feel too comfortable with going any higher
If the tyre manufacturer states they are good for 81 psi, it means they tested them up to (and even beyond) that pressure.

Are they dedicated truck or van tyres ?
Those have a higher psi-rating.
__________________
Strayed to the Dark Diesel Side

  Reply With Quote
The Following User Says Thank You to euromodder For This Useful Post:
ktaylor (03-04-2011)
Old 03-04-2011, 03:39 AM   #50 (permalink)
Tire Geek
 
CapriRacer's Avatar
 
Join Date: May 2008
Location: Let's just say I'm in the US
Posts: 767
Thanks: 3
Thanked 355 Times in 219 Posts
I think you've read the sidewall incorrectly

Quote:
Originally Posted by ktaylor View Post
I have a question, what is the limit to inflating tires. My Nokian WR's have a max sidewall of 81 psi and are currently inflated 50/45 F/B. I don't feel too comfortable with going any higher but I keep reading in the forum "just bring it to max sidewall." Also, were do I buy a good pressure gauge? Like Home-depot, or Canadian Tire?
I think you've read the sidewall incorrectly. Look again, and I think you'll see it says 51 psi!

  Reply With Quote
Reply  Post New Thread


Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Longtime Lurker Looking for Miles ZX40 Electric Micro van mods & information rmay635703 Fossil Fuel Free 49 07-06-2014 10:27 PM
Tire / Wheel Mods? NeilBlanchard EcoModding Central 10 09-30-2009 04:24 PM
Tire pressure and fuel economy RESULTS 07b2300 EcoModding Central 56 10-31-2008 12:40 PM
NASA sponsored competition rewards efficiency mods in private aircraft MetroMPG General Efficiency Discussion 0 08-13-2008 10:35 AM
Getting more efficiency out of a ZX2. Small list of mods and driving tips for it. koihoshi EcoModding Central 9 07-20-2008 04:26 AM



Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2022, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com