Or you could just drive past about 5 mile markers
on the freeway and see what your odometer says
but then I'm naturally lazy. :oD

----- Original Message -----
From: "Larry Alofs" <lalofs@ENTERACT.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Wednesday, June 27, 2001 8:11 AM
Subject: Re: The dreaded topic..(larger tires on rear?)

> "Paul M. Hillbish" wrote:
>
> > Tires. I have a question about tires. On the front, I have a different
size
> > tire than on the rear. The wheels are the same size though. My question
is,
> > how will this effect performance? Being that I am poor, I will not be
> > replacing the tires very soon, but I am wondering, should I have the
larger
> > ones on the drive wheels? Any thoughts on this?
> >
> > --Paul--
>
> Paul:
>  Assuming that your van is 2 wheel drive, this is not a big issue.
>   If there is any difference in the load rating or max psi , put the pair
with
> the largest numbers on the rear.
>   Putting the best tread on the front will give you better braking on wet
> pavement.
>   Having the tires with the largest overall diameter on the back will give
you
> a little better mileage on the hiway but a little less acceleration at low
> speeds.  Calculating the gas mileage from odometer readings, however, will
not
> detect a difference because it only counts wheel revolutions not actual
forward
> progress.
>   You didn't state the actual tire sizes.  All 3 numbers determine the
overall
> diameter.  Often increasing the first number and decreasing the second
number
> can give about the same diameter, depending on tread wear and pressure,
etc.
>   To compare, you could measure carefully how far the van moves forward
for
> exactly one turn of a tire while supporting the expected load with the
proper
> pressure.
>
> Larry A.