View Single Post
Old 09-10-2008, 04:27 PM   #20 (permalink)
tasdrouille
Master EcoModder
 
tasdrouille's Avatar
 
Join Date: Jan 2008
Location: Mirabel, QC
Posts: 1,672

The Guzzler - '08 Hyundai Elantra GL
90 day: 33.12 mpg (US)

Got Soul? - '11 Kia Soul 2U
Thanks: 35
Thanked 86 Times in 57 Posts
Quote:
Originally Posted by Hasbro View Post
Is this because some of the resistance is eliminated or that more stress is put on the bearings?
My reply was based on the reasoning that as you reduce the rolling resistance of one component the relative proportions of other components to total rolling resistance increase.

The correct numbers are:

Brakes: 6%
Bearings and seals: 12%
Tires: 82%

Assuming 32 psi in the tires.

It is estimated that rolling resistance in a tire is reduced by 7% for every 0.3 bar pressure increase (~4.35 psi). Pump those tires to 45 psi and the rolling resistance is reduced by roughly 20%. The numbers now become:

Brakes: 7.5%
Bearings and seals: 15%
Tires: 77.5%
__________________



www.HyperKilometreur.com - Quand chaque goutte compte...
  Reply With Quote