Vanagon EuroVan
Previous messageNext messagePrevious in topicNext in topicPrevious by same authorNext by same authorPrevious page (November 2007, week 2)Back to main VANAGON pageJoin or leave VANAGON (or change settings)ReplyPost a new messageSearchProportional fontNon-proportional font
Date:         Tue, 13 Nov 2007 15:19:46 -0800
Reply-To:     Brendan Slevin <brendan@BELLATAZZA.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Brendan Slevin <brendan@BELLATAZZA.COM>
Subject:      Re: Hid AUX lamps GoWesty's headlight upgrade kit
Comments: To: Michael Elliott <camping.elliott@GMAIL.COM>
In-Reply-To:  <473A2F34.4020804@gmail.com>
Content-Type: text/plain; charset="us-ascii"

How many watts brighter is Mike S than Mike E and how does it relate to MPG increasing?

:)

Brendan

-----Original Message----- From: Vanagon Mailing List [mailto:vanagon@GERRY.VANAGON.COM] On Behalf Of Michael Elliott Sent: Tuesday, November 13, 2007 3:12 PM To: vanagon@GERRY.VANAGON.COM Subject: Re: Hid AUX lamps GoWesty's headlight upgrade kit

Coolness. I knew all I had to do was to make an amateurish stab at the math and someone who knows a lot more than I would provide the real numbers. Thanks, Mike!

-- Mike "Rocket J Squirrel" Elliott 71 Type 2: the Wonderbus 84 Westfalia: Mellow Yellow ("The Electrical Banana") 74 Utility Trailer. Ladybug Trailer, Inc., San Juan Capistrano KG6RCR

On 11/13/2007 3:06 PM Mike S wrote:

> At 05:32 PM 11/13/2007, Michael Elliott wrote... >> So, how important is the difference between 160 or 300 Watts of power >> going to the headlights when compared to 100,000 watts moving the van? > > The point is valid, but some math is missing. > > The useful BTU capacity of gasoline is reduced by the fact that engines > are very much less than 100% efficient, and there are also drivetrain > losses before any energy is used to move the car. > > 20% efficiency is in the ballpark, so we're talking about 20K Watts > actually being used. An A/C Vanagon has a maximum output of 67 HP, or 49 > KW, and would cruise at some fraction of that (1/3?) , so all of those > figures seem to be reasonable. > > 140 Watts of 12V power from the alternator is more than that from the > engine, because alternators, too, are not 100% efficient. 55% is a > reasonable ballpark, to that 140 W of DC takes ~250W of engine power. > > 250W / 20KW = 1.25% > > If a Vanagon gets 20 MPG, then the savings would be about the same as > getting an extra 1/4 MPG. >


Back to: Top of message | Previous page | Main VANAGON page

Please note - During the past 17 years of operation, several gigabytes of Vanagon mail messages have been archived. Searching the entire collection will take up to five minutes to complete. Please be patient!


Return to the archives @ gerry.vanagon.com


The vanagon mailing list archives are copyright (c) 1994-2011, and may not be reproduced without the express written permission of the list administrators. Posting messages to this mailing list grants a license to the mailing list administrators to reproduce the message in a compilation, either printed or electronic. All compilations will be not-for-profit, with any excess proceeds going to the Vanagon mailing list.

Any profits from list compilations go exclusively towards the management and operation of the Vanagon mailing list and vanagon mailing list web site.