Date:         Sat, 14 Aug 2021 13:50:34 +0000
Reply-To:     Dennis Haynes <d23haynes57@HOTMAIL.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Dennis Haynes <d23haynes57@HOTMAIL.COM>
Subject:      Some thoughts for tires and tire pressure and other stuff.
Content-Type: text/plain; charset="us-ascii"

As a starter one should minimalize the differences between a "tin top" and camper. For any year both have the same max axle weight and total weight ratings. Syncros have higher ratings. Doing some math the maximum total of both axles exceeds the max total weight for the vehicle so both axles shall never be fully loaded. So now take a 7 passenger van, add a large adult to the left of both rear seats and you have the weight of a Westy. Add a large battery under the rear seat left side and you have a Westy with a full water tank. Yes, there is only about 400 pounds difference.  Throw 2 batteries between the front seats and a large one center of the rear seat and you have a Syncro.

Here is a shot of the scale readings of a 1991 Westy after leveling, and me sitting in the left rear seat. Note this includes a 200 A/H battery in drop down tray near the sliding door. Adding 2 passengers up front makes the camper front heavy.
https://1drv.ms/u/s!AqaEiIhKCAKbkdgnwuxXgyNmiccpLQ

As for proper inflation pressure the factory recommendation is likely based on what is required to carry the load and some desired handling characteristics. Understeer is part of that design. Better to slid into something instead of a spin out causing much more hazardous results.

The construction of a tire is only a small part of the package for load carrying capacity. Impact resistance aside the ability to carry a load is limited by heat generation and dissipation. Tire diameter, (revolutions per mile/minute), width, (load displacement), and the pressure/volume of air are the main factors. While tire design (some magic) has an effect on where a tire flexes and the heat generated, it is the combination of size and pressure that determine how much flex and resulting heat is generated. A thicker sidewall tire at a given speed, load, inflation pressure will generate more heat. So where a passenger car tire can meet the full load rating at 32 or 35 psi, the LT tires actually need higher pressures to do the same job.   Here is a link for the tire replacement guide. Look for the load inflation table for the tire you are using.
https://1drv.ms/b/s!AqaEiIhKCAKbhZ9SbG0bB9pQVKL-Iw?e=uaGo9a

For tire and wheel upgrades if not confident partner with someone who will take some responsibility. There are a lot of options. For road touring use I have been using 17's since 2009. It is harder to find wheel choices that can hide the 2WD front hubs, have proper offset and adequate load capacity. Many aftermarket wheels are only rated to 1,300 or 1,400 pounds. I like to see ratings close to the tire being used. For the off road/all-terrain there are often more tire choices in 16's. Using spacers is becoming helpful. You also have to consider wheel mounting. Especially with spacers longer bolts-studs maybe required. If considering a brake upgrade combine with the wheel upgrade so you only deal with the studs once.

Dennis