Date: Tue, 25 Oct 2011 08:26:21 -0700
Reply-To: "English II, Bill" <bill.english@THERMOFISHER.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: "English II, Bill" <bill.english@THERMOFISHER.COM>
Subject: Re: Aerodynamics related to fuel consumption (for an 84 tin top)
In-Reply-To: <CAHTkEuK61t7YVwm35WF6Vz9OHejnjEhSk2pW06Qq5A===KLJew@mail.gmail.com>
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We have a 91 Multivan (day-camper) with a 2.4 liter GoWesty engine and custom manual 5-spedd tranny with locking differential.
Vehicle is lifted and has large wheels.
No roof racks, but we do have a Yakima swing out bike rack on a hitch.
The average gas mileage is probably around 16 MPG.
With the gas pedal fully down on windy strips of road the mileage plummets to approx 10 or 11 MPG.
The van symptom is inability to exceed 75 to 80 MPH because of headwinds, gas pedal doesn't improve speeds after some point.
When the environment is more favorable, the van is able to cruise fully loaded with gear and hit 80 MPH easily, some to spare with RPM on right edge of green.
I don't get any sense of saving gas with alterations to the van aerodynamics.
Bill
Santa Cruz Mountains, Boulder Creek, South of Big Basin St. Park
91 Westy Multivan, an ultimate utilitarian vehicle.
87 Vanagon
82 Transporter
67 Transporter panel van
________________________________________
From: Vanagon Mailing List [vanagon@gerry.vanagon.com] On Behalf Of Don Hanson [dhanson928@GMAIL.COM]
Sent: Tuesday, October 25, 2011 7:32 AM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Aerodynamics related to fuel consumption (for an 84 tin top)
I also have a Yakima bike rack on my van, but on the rear hatch, down in
the "hole" the van creates in the air-stream. Mounted back there In that
area, I've seen no significant difference in fuel economy...even when I have
3 bikes and 5 or 6 detached spare wheels mounted. The hatch-mounted rack is
easier to use than a roof rack, also...though with bikes mounted, the hatch
becomes more difficult to lift and it needs a prop to stay open reliably.
Also, when you travel dirt roads, the low pressure area behind the van
really creates a 'dust vortex'. Bikes mounted on the rear get quite filthy
in a short time. Since that hatch-mounted rack is not really a factor in
gas consumption, I normally just leave it on there, ready to use when I have
no room inside for my bikes.
There is nothing 'cheap', nothing silly about trying to spend effectively
on fuel, in my humble opinion. Those 2 miles per gallon that I discovered
can be saved by removing my roof rack, if I don't need it, that might seem
petty...but my math shows me I'll have saved $600 (+/-) by 'paying just a
little attention'..... I can better spend $600 a year else where. 2mpg
saved is (very roughly) 10% of my verified gas mileage. I log appx. 30k
in my van every year. That 10% is 3000 miles, or about 150 extra gallons
burned, and gasoline costs $4/gallon now. I guess I can take a few minutes
to remove and stash my roof rack to save $600 or to get an additional 3000
miles of traveling in. (Portland, Or. > Baja and back?)
On Tue, Oct 25, 2011 at 4:19 AM, Stephen Grisanti <bike2vcu@yahoo.com>wrote:
> I was a rep in the bike biz for about 15 years, a job that practically
> demands a full-dress roof rack. Over the years I used three different racks
> on a Nissan Sentra, a Nissan pickup with a shell, a Ford Aerostar minivan
> and a Mopar minivan. Interestingly, the two vans experienced the greatest
> sensitivity to gas mileage with the racks installed. Averaging 1,000 miles
> a week it was not too much work to remove a rack if it was not going to be
> needed that week in order to save a little gas, and that was when gas cost
> 1/3 to 1/2 what it does now. Wind noise was an issue as well.
>
> Stephen
>
> --- On Tue, 10/25/11, Danny C. <bruiserbabie@YAHOO.COM> wrote:
>
> From: Danny C. <bruiserbabie@YAHOO.COM>
> Subject: Re: Aerodynamics related to fuel consumption (for an 84 tin top)
> To: vanagon@GERRY.VANAGON.COM
> Date: Tuesday, October 25, 2011, 12:18 AM
>
> Seriously!!! your worried about what drag there is on a roof rack. WOW!!!
>
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