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Subject:Re: An interesting article on gas mileage vs wheel size
From:Ken Lewis
Date:Sun, 30 Oct 2011 16:32:10 -0400

Two wheel drive DOKA.

Offset is 42. I arrived at the back spacing by dividing the width,
7.5"(190.5mm) by two and adding the offset. A formula I found in the Vanagon
archives. I "assumed" it to be correct.
Ken

----- Original Message -----
From: "BenT Syncro" <syncro@gmail.com>
To: "Ken Lewis" <kdlewis@NORTHSTATE.NET>
Cc: <vanagon@GERRY.VANAGON.COM>
Sent: Saturday, October 29, 2011 3:32 PM
Subject: Re: An interesting article on gas mileage vs wheel size

Putting on a 2wd? Do you have the offset rather than a measured or
calculated backspace? It's the figure that says 'ET' followed by a couple of
numbers. I'd like to help but don't want to rely on the expression of offset
as backspace because accuracy can be affected by how you arrived at that
number IMHO.

BenT

sent from my electronic leash

On Oct 29, 2011, at 9:43 AM, Ken Lewis <kdlewis@NORTHSTATE.NET> wrote:

> I found this article while researching what it would take to get 17"x7.5"
> Audi A4  wheels to work on my crewcab.
>
> This line caught my eye;" What's immediately apparent from the results is
> that as the wheel-and-tire packages get larger and heavier, acceleration
> and
> fuel economy suffer. Neither is a huge surprise, but we measured a
> 10-percent drop in fuel economy and a four-percent degradation in
> 0-to-60-mph acceleration from the 15s to the 19s".
>
> I  looked at  these this morning.
> http://winstonsalem.craigslist.org/pts/2618213904.html . Nice looking BIG
> wheels. Some road rash. He also has the longer lug bolts.
>
> The bolt hole size is good but it appears the center bore (~57mm) would
> need
> to be opened up. I need to actualy take a front wheel off my truck and do
> some measuring . I have read the grease cap can be shortened to get rid
> of
> the lip.
>
> I arrived at a  back spacing of 137.25mm on the Audi wheels . By my
> calculations I would need a 14mm spacer? Anyone?
>
> Thanks Ken