Go Back   EcoModder Forum > EcoModding > Hypermiling / EcoDriver's Ed
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 10-25-2010, 11:32 PM   #1 (permalink)
EcoModding Lurker
 
Join Date: Aug 2010
Location: Mississauga
Posts: 80
Thanks: 0
Thanked 2 Times in 2 Posts
How much tire pressure and grill block question

Ok I have a 2006 chevrolet optra and the tires are rated at 44psi I have them at 50 how do I tell the strength of the side wall to over inflate them and improve economy? I'm also wondering if I should inflate the tires cold (I have a pump strong enough to do it) or hot? Due to the fact that as air rises in tem so dose the presure. I'm hoping to build a gril block for the winter to help the engin warm up.

__________________
2 cars one never gets driven the other is an MPG project already at 5% increase in standard driving economy CAI and Pulstar plus. Thinking weight reduction next year.
  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 10-26-2010, 12:29 AM   #2 (permalink)
EcoModding Apprentice
 
Join Date: Oct 2010
Location: New Zealand
Posts: 119

Laura the Lancer - '81 Mitsibishi lancer LX
Thanks: 0
Thanked 27 Times in 8 Posts
a grill block is a good idea to warm the car up quickly, unfortunately it wont help warm the tyres up quicker, tyres use friction and brake heat to warm up,
i would pump them up when they are warm, that is what i do , seems to work quit well
  Reply With Quote
Old 10-26-2010, 06:19 AM   #3 (permalink)
Tire Geek
 
CapriRacer's Avatar
 
Join Date: May 2008
Location: Let's just say I'm in the US
Posts: 733
Thanks: 1
Thanked 320 Times in 201 Posts
Quote:
Originally Posted by Creeper View Post
Ok I have a 2006 chevrolet optra and the tires are rated at 44psi I have them at 50 how do I tell the strength of the side wall to over inflate them and improve economy? I'm also wondering if I should inflate the tires cold (I have a pump strong enough to do it) or hot? Due to the fact that as air rises in tem so dose the presure. I'm hoping to build a gril block for the winter to help the engin warm up.
You didn't tell us what the vehicle tire placard says for pressure. That might affect the answers that you get.
  Reply With Quote
Old 10-26-2010, 07:23 AM   #4 (permalink)
EcoModding Lurker
 
Join Date: Jan 2010
Location: Finland
Posts: 18
Thanks: 1
Thanked 0 Times in 0 Posts
Side wall marks are usually for cold tyres. "Cold = the open air temperature"
  Reply With Quote
Old 10-26-2010, 08:25 AM   #5 (permalink)
EcoModding Apprentice
 
Join Date: Oct 2009
Location: Arab, Alabama
Posts: 174

Cool Running - '17 Chevrolet Bolt Premier
Thanks: 33
Thanked 27 Times in 16 Posts
My tires are rated 44 PSI on the sidewalls. I keep them pumped up to 52 PSI cold. They are wearing okay, mileage is okay, car rides somewhat rougher. It's a tradeoff I can live with.
__________________
  Reply With Quote
Old 10-26-2010, 09:43 AM   #6 (permalink)
Master EcoModder
 
Join Date: Sep 2010
Location: Foothills near Denver
Posts: 279

RSX2fast4mpg - '02 Acura RSX Type S
90 day: 38.22 mpg (US)

bubbatrucker - '98 Chevrolet K1500
90 day: 18.1 mpg (US)
Thanks: 15
Thanked 25 Times in 17 Posts
The general rule for tire manufacturers is tire pressure on the sidewall is cold and you'll get 4-6psi as the air expands during normal driving (usually in 1-2 miles). 52psi cold is significantly over the rated pressure. The most likely consequence is going to be early tread wear on the center of your tire, but it also effects traction and handling. I'd be comfortable with 4psi over in the summer, but I stick with the sidewall rating during the winter (I live in snow and ice country).

Also, realize that being 8psi over is probably not buying you more than a single MPG and maybe not even that. If you were driving around at 20psi, more than likely it would only cost you 1-1.5mpg. You're better off investing your time and energy into the grill block, driving technique and aeromods, thus saving yourself the expense of having to replace tires more often because they're wearing faster.
  Reply With Quote
Old 10-26-2010, 09:45 AM   #7 (permalink)
Hypermiler
 
PaleMelanesian's Avatar
 
Join Date: Dec 2007
Location: Texas
Posts: 2,305

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

PaleFit - '09 Honda Fit Sport
Team Honda
Wagons
90 day: 44.4 mpg (US)
Thanks: 594
Thanked 416 Times in 273 Posts
Cold. That's what the tires are rated for, and what the car calls for. If you set the pressure when they're hot, the next morning you're underinflated.

Tire wear: higher pressure has not worn my tires in the middle on my last three sets. I've found it to extend the life of the tires as well. These are all passenger tires, LT might be different.
__________________



11-mile commute: 100 mpg - - - Tank: 90.2 mpg / 1191 miles
  Reply With Quote
Old 10-26-2010, 12:21 PM   #8 (permalink)
Smeghead
 
Join Date: Oct 2009
Location: South Central AK
Posts: 933

escort - '99 ford escort sport
90 day: 42.38 mpg (US)

scoobaru - '02 Subaru Forester s
90 day: 28.65 mpg (US)
Thanks: 32
Thanked 145 Times in 97 Posts
my tires are rated at 50psi and I have them at 55 psi after a 5 mile drive to the station. I will be dropping them back down into the 40s soon though as I get some wicked wheel hop in the ice and snow.

I have had soft winter tires for a whole year now (used them in the summer) Other than some very rapid wear due to a very bad alignment issue they have worn flat across.

One thing tire manufacturers have to contend with is varying speeds traveled. The faster the car goes the higher the temperature of the tire. They calculate the increase in pressure for a vehicle at the max weight of the tire traveling at the speed rating of the tire.
__________________

Learn from the mistakes of others, that way when you mess up you can do so in new and interesting ways.

One mile of road will take you one mile, one mile of runway can take you around the world.
  Reply With Quote
Old 10-26-2010, 03:39 PM   #9 (permalink)
eco....something or other
 
Join Date: Jul 2009
Location: Colfax, WI
Posts: 707

wood hauler - '91 Ford F-250
Team Pontiac
90 day: 18.97 mpg (US)

Rav - '06 Toyota Rav4 Base
90 day: 26.52 mpg (US)
Thanks: 38
Thanked 56 Times in 43 Posts
I have not seem more than 1 psi increase in pressure from cold to hot. They seem to run cold all the time. 50 psi is 50 psi for me. Tires have steel belts around them to hold them in shape. I have never seen a tire wear out in the center from being set a few lbs over pressure. My tires are wearing flat....just like they are supposed to.

EDIT: I borrowed a friend's flat bed trailer a few months ago to haul the tractor. I checked the tires before leaving and my air gauge exploded in my hand!!!! It was an 80 lb gauge too. It had well over 150 lbs in the tires and they were wearing flat. He hauls VERY heavy loads on occasion, and so he leaves them "fully inflated". These tires are half worn down as they have seen many miles, but they are wearing flat.
__________________



1991 F-250:
4.9L, Mazda 5 speed, 4.10 10.25" rear
  Reply With Quote
Old 10-27-2010, 09:10 AM   #10 (permalink)
Hypermiler
 
PaleMelanesian's Avatar
 
Join Date: Dec 2007
Location: Texas
Posts: 2,305

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

PaleFit - '09 Honda Fit Sport
Team Honda
Wagons
90 day: 44.4 mpg (US)
Thanks: 594
Thanked 416 Times in 273 Posts
Quote:
presuer
speling

__________________



11-mile commute: 100 mpg - - - Tank: 90.2 mpg / 1191 miles
  Reply With Quote
Reply  Post New Thread


Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Lower Grill Block 2005 Honda Civic Arminius EcoModding Central 12 10-04-2011 12:31 AM
grill "shield" rather than block? lunarhighway Aerodynamics 70 12-17-2010 03:50 AM
Grill Block question? chipX Aerodynamics 31 03-11-2009 03:47 PM
96-00 Civic Upper Grill Block Impulse Aerodynamics 2 07-12-2008 03:09 PM
pressure sensors for testing grill blocks? pasadena_commut Aerodynamics 15 07-10-2008 11:34 PM



Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com