View Single Post
Old 06-16-2010, 08:46 AM   #14 (permalink)
RobertSmalls
Left Lane Ecodriver
 
RobertSmalls's Avatar
 
Join Date: Aug 2008
Location: Buffalo, NY, USA
Posts: 2,257

Prius C - '12 Toyota Prius C
Thanks: 79
Thanked 287 Times in 200 Posts
Quote:
Originally Posted by AeroModder View Post
Now, is the increase in rolling resistance enough to counteract inertia? Or does the increased resistance to change speed overcome the rolling resistance?
http://ecomodder.com/forum/tool-aero...ToStep=5-200-5

About a third of the load at 60mph is rolling resistance for the above-linked car. So a 3% increase in mass (here, 90lbs) should bring a 1% increase in fuel consumption on a flat road with no stops or hills. It's a small impact, but every little bit helps (or hinders).

Also, inertia is bad for fuel economy. It makes DWB harder, it moves your RPMs upward during acceleration, raises the stakes every time you brake, and it makes you downshift on too steep of a hill climb. The only good thing about it is that it makes P&G easier with longer pulses and longer glides.
  Reply With Quote