Date:         Tue, 2 Jul 96 17:27:58 -0700
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         Bren Smith <bren@ccnet.com>
Subject:      Re: 91 ride, (was:No Subject)

>> Well, here's the scoop: I'm riding Goodyear Regatta touring tires, size
>> P195/70R14 @ 36 psi all around. Based on the simple shock test mentioned
>> above, my shocks seem to be fine. How could I tell if the tires are
>> reinforced, or would that even make a difference?
>  
>These tires are not reinforced nor are they even the correct size.  Load
>capacity information is stamped on the sidewall.  In addition, when using
>passenger car tire(size atarts with the letter"P", Light truck tires start
>with "LT") you need to derate another 10% according to the feds.  Your tires
>are rated at 1332 punds -10% leaves a capacity of 1198 pounds.  4 X 1198 =
>4792.  Your vehicles wieght (GVWR) is over 5500 pounds.  Your tire
>combination is overloaded indeed.  The Regatta's are available in 215/70 -14.
>These are rated to carry 1554 pounds each.  Even with the derating, they
>will safely carry your Van.

To add to what Dennis has said, here's something for decoding tires that 
I've found real helpful. Thanks to Jeff Berton for this info.:

===================
For tires using the P-metric designation (e.g., P245/50ZR16)

Format:

  [Code][Width]/[Aspect][Speed][Construction][Size]

Code:

  P   = Passenger
  LT  = Light truck
  T   = Temporary
  LTP = Light truck, personal use

Width:

  Width at widest point, sidewall to sidewall, in millimeters

Aspect Ratio:

   Tire height in mm, measured tread to bead, divided by width above,
   multiplied by one hundred.

Speed ratings:

(The maximum speed the tire can maintain at its maximum load rating)
  Q - 100 mph
  R - 106 mph
  S - 112 mph
  T - 118 mph
  U - 124 mph
  H - 130 mph
  V - 149 mph
  W - 168 mph
  Z - more than 168 mph

Construction:

  R - Radial ply
  B - Bias belted
  D - Diagonal bias

Size:

  The diameter of the wheel the tire is designed to be mounted on, in 
inches.

Other information:

  Maximum Air Pressure - This is the max pressure the tire is designed to 
hold
                         (note this is more than the recommended inflation
                         pressure)

  Maximum Load         - Weight the tire can support

  Load Index           - A code that indicates the maximum weight the 
tire can
                         carry at its speed indicated by its speed rating

  Construction         - Tells the number and type of plies used in the
                         construction of the tread and sidewall

  DOT Serial Number    - Identifies the plant, manufacturer, and date of
                         production

  Tread Wear Index     - A rating of the tire's resistance to wear.  100 
is the
                         reference.  A 250 rating indicates 2.5 times the 
wear
                         resistance of the reference tire.  This number 
cannot
                         be accurately translated to mileage.

  Traction Index       - A rating of the tire's ability to stop on wet 
pavement.
                         There are three grades, A, B, and C, with A 
being the
                         best.  This index does not reflect the tire's 
traction
                         performance on dry, snowy, or icy pavement.

  Temperature Index    - A rating of the tire's ability to dissipate and 
resist
                         heat.  There are three grades, A, B, and C, with 
A
                         being the best.

=========================================================================
Bren Smith        |4 Orinda Way, Bld. C |510/253-3048 tel |'76 dual cab
Dantz Development |Orinda, CA 94563     |510/253-9099 fax |bren@ccnet.com
=========================================================================