In a message dated 98-06-08 21:32:10 EDT, dearbo@EROLS.COM writes:

<< Hmmm - I just did the same (increased tire diameter by 2") on a 4x4 that
 I have and got the same results.  Quiet on the flats, downshifts more on
 hills - less torque. I haven't checked the speedo yet. It should be going
 faster than the speedo indicates - right?  Also the milage trip meter
 will be off so its going to be difficult to determine gas milage.  I was
 going to do some conversions of RPM to mph as I made up a little chart of
 "before" readings: 2000rpm = 50 mph in top gear but I'm getting the same
 readings after the tire diameter increase. Any ideas on this?

 Gary
 88GL, 80Westy
  >>

 Gary, no matter what tire size you put your sycro, the speedo will always
read the same. That's because your speedo cable runs to your front
differential. Imagine your car up in the air on a hoist, the wheels are off,
the car is running and you put it in 4th gear and bring it up to 4000 RPM,
you'll will see about 70 MPH. Now imagine big huge monster tuck tires on the
syncro with the same test as above, nothing changes right.  Non syncro
vanagons have the speedo cable running to the left front wheel, so any
dramatic tire size changes will really effect the indicated speed on the
speedo. The bigger the tire, the less speed they will indicate, the smaller
the tire, the faster it'll indicate. Either way, on both cars you'll need to
figure out actuall speed and adjust the speedo's accordingly.  Have fun.
 Michael Modl. 87 syncro. ( 16" rims, with 215-65-16 tires, at 4000 RPM =
72MHP, actual speed = 75 MHP. )