View Single Post
Old 11-04-2012, 02:32 PM   #27 (permalink)
Mustang Dave
Intermediate EcoDriver
 
Mustang Dave's Avatar
 
Join Date: May 2009
Location: Northern Arizona - It's a DRY cold..
Posts: 671

Trigger - '07 Ford Mustang V6 Premium Coupe
Team Mustang
Sports Cars
90 day: 32.76 mpg (US)

Big Red (retired) - '89 Ford F-250 4wd Custom
90 day: 18.13 mpg (US)

Big Red II - '13 Ford F-150 FX4
Pickups
90 day: 19.61 mpg (US)
Thanks: 163
Thanked 129 Times in 102 Posts
Quote:
Originally Posted by wungun View Post
So your saying, in my example, if it requires 50hp to do 50 mph, you'll need 400hp to do 100??
I think you're wrong....
Are you thinking of kinetic energy an object has at speed perhaps?
Or am I!?
Lol
You are.

From Wikipedia:

"Power

The power required to overcome the aerodynamic drag is given by:


Note that the power needed to push an object through a fluid increases as the cube of the velocity. A car cruising on a highway at 50 mph (80 km/h) may require only 10 horsepower (7.5 kW) to overcome air drag, but that same car at 100 mph (160 km/h) requires 80 hp (60 kW). With a doubling of speed the drag (force) quadruples per the formula. Exerting four times the force over a fixed distance produces four times as much work. At twice the speed the work (resulting in displacement over a fixed distance) is done twice as fast. Since power is the rate of doing work, four times the work done in half the time requires eight times the power."

This is well known among salt flat racers.
__________________
Fuel economy is nice, but sometimes I just gotta put the spurs to my pony!



Quote:
Originally Posted by thatguitarguy View Post
Just 'cuz you can't do it, don't mean it can't be done...
Quote:
Originally Posted by elhigh View Post
The presence of traffic is the single most complicating factor of hypermiling. I know what I'm going to do, it's contending with whatever the hell all these other people are going to do that makes things hard.
  Reply With Quote