View Single Post
Old 04-13-2009, 08:05 PM   #23 (permalink)
bwilson4web
Engineering first
 
bwilson4web's Avatar
 
Join Date: Mar 2009
Location: Huntsville, AL
Posts: 788

14 i3-REx - '14 BMW i3-REx
Last 3: 45.67 mpg (US)

17 Prime Plus - '17 Toyota Prius Prime Plus
90 day: 58.25 mpg (US)
Thanks: 75
Thanked 194 Times in 125 Posts
Quote:
Originally Posted by Ernie Rogers View Post
Wow, Bob, that's a fantastic idea! I can see it! You put the tire on a loose wheel, pump it up to pressure, then measure how high it bounces when you drop in on a smooth concrete surface! Or, see how the bounce changes with the kind of pavement. Lots of possibilities here.

Someone should sit down and work out the math, to see how you convert. . . .
I was thinking more along the line of a Rockwell hardness tester approach only using a ball instead of conical tip:
Rockwell hardness testers in portable, bench and automatic digital hardness testers

The idea is to measure the tread material elastic recovery to get an idea of the hysteresis loss. But Michelin did a similar demonstration a year or so ago.

They had two large cars, one with low rolling resistance tires and the other without. They set them on identical "U" tracks in neutral and started them rolling. The low rolling tire car stopped last.

Bob Wilson
__________________
2019 Std. Range Plus Model 3 - 134 MPG3 || 2014 BMW i3-REx - 117 MPGe, 39 MPG
JuiceBox 40 Pro (240 VAC, 40 A), KHONS portable (120-240 VAC, 12-32 A)
Retired engineer, Huntsville, AL (five times AutoPilot saved.)
  Reply With Quote