Date: Wed, 17 Aug 2005 16:57:06 -0700
Reply-To: Jake de Villiers <crescentbeachguitar@TELUS.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Jake de Villiers <crescentbeachguitar@TELUS.NET>
Subject: Re: How much fuel efficiency gained by shedding 300 lbs?
Content-Type: text/plain; charset="iso-8859-1"
Sorry Brandon. I know you are Canadian and all, but there IS one magic
formula that covers all cars. The value that changes is Cd, Cx in Europe,
and is derived from wind tunnel testing. If I had the time, or if I thought
it mattered, I would look it up in my old Car and Driver magazines,
but........
The faster you go, the more wind resistance, the more fuel burned. I don't
quite understand the discussion anyway. I like poking along on two lane
roads, smelling the crops and stopping at will. I feel sorry for the drones
ripping down the highway at 85mph in their suv's, tinted windows and A/C
keeping the real world at a distance. I love the real world and relish
every chance to experience it anew. At 55mph and 25 mpg in my van. Seeya,
Jake
----- Original Message -----
From: "Brandon" <Brandon@CONCILIO.CA>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Wednesday, August 17, 2005 2:05 PM
Subject: Re: How much fuel efficiency gained by shedding 300 lbs?
> so then the 2 conditions that must be met are:
> - same shape
> - same surface area
>
> correct?
>
> If so, I would argue that no 2 cars models have those in common and thus
> the wind resistance for each car is unique. As a result, no one magic
> formula can accurately account for how fuel inefficient all vehicles are
> unless it includes some kind of unique variable specific to that model of
> vehicle.
>
> as a side, I think what you meant to say was that the density of an object
> has no bearing on it's wind resistance. Which is true. However the higher
> the density the more energy it will take to change it's relative position
> i.e. - Accelerating from 0 to 65 MPH
>
>
> > I think he meant, a 6 ton flat brick has the same wind resistance as a
> > 200g flat brick. ;)
> >
> > On 8/17/05, Brandon <Brandon@concilio.ca> wrote:
> >> so by that logic a 1 pound Tear dropped shaped object has the same wind
> >> resistance as a 6 ton flat brick.
> >>
> >> note: our vans more closely resemble the brick :)
> >>
> >>
> >> > My goodness you guys, nobody is thinking, and I can't sit quietly any
> >> > longer!
> >> >
> >> > The mass of the vehicle does not change the wind resistance, or the
> >> MPG,
> >> > on
> >> > the highway. Stop and go or big hills is another story, but on flat
> >> ground
> >> > at steady speed the van could be 6 tons and you'd get the same MPG.
> >> >
> >> > At steady speed you are not accellerating the mass, you are only
> >> pushing
> >> > the
> >> > wind out of the way, so mass doesn't matter.
> >> >
> >> > John
> >> > Aircooled.Net Inc.
> >> >
> >> >
> >>
> >
> >
>
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