Tire size alone does not determine capacity, but the size/load ratings are
standardized.  The load rating is also stamped on the tire side wall along
with the traction, temp, and speed ratings.  Actual dimension do vary
slightly by manufacturer but the ratings are consistent.  Remember also,
that when use a passenger tire on a light truck application,  you must
de-rate the tire by 10%.  As for you math, you are correct, but check the
tire you are considering fore the actual dimensions.  Each manufacturer has
a table listing their dimensions for their tires.

Dennis

-----Original Message-----
From: Mark McCulley <raven@HALCYON.COM>
To: Vanagon@VANAGON.COM <Vanagon@VANAGON.COM>
Date: Sunday, August 02, 1998 12:17 PM
Subject: Re: vehicle weight/tires

>At 12:02 AM 8/2/98 -0400, Dennis Haynes wrote:
>>A 215-70/14 is rated at 1554.
>Tire size alone does not determine load capacity does it?
>
>>225-70/14's are becoming available again.  I believe these are
>>rated at 1675lbs. This is also a great way to increase
>>the tire diameter (27.5") without replacing the wheels.
>According to my calculation, a 225-70/14 tire will have a diameter of 26.4"
>which is about 1" larger than the stock Vanagon tires. Here's the
calculation:
>
>(((225 / 25.4) * 0.70) * 2) + 14 = 26.40
>
>-Mark