With the help of Joel's library, the wear index is more or less complete.
  
  The only prediction which came true was that of the 4 spd. Diesel having
  the highest wear index number a 2069 ft./mile. Now we know why it has an
  oil cooler. What is lowest??? W. Kennedy's 911 conversion, when he had the
  2.2 liter engine in it! This takes the cake at 1330 ft./mile and is getting
  down into linehaul Diesel truck territory (in the 1200s). Next lowest is the
  2.7 911 conversion at 1419 with the 2.0 air-cooled Vanagon right behind it at
  1431. 
  
  There may be an exception though. The references (Bentley and a german book of
  Joel's) do not agree on ratios for the wasserboxers up to '95. Bentley implies
  that the wasserboxers did not get the 091/1 gearbox until '95 and would there-
  fore have had the 091 box giving a wear index of 1391 ft./mile IF the ratios
  weren't changed from the air cooled values. The german reference shows all
  wasserboxers as having the 091/1 ratios. The Bentley view puts the 1.9
  wasserboxer as the lowest wear index of all standard (not converted) models.
  
  Can anything be learned from this? IMHO, Syncro owners would be well advised
  to monitor oil temperature, Prospective Diesel shoppers should wait for that
  5 speed and, well, that 911 conversion now calls siren-like form the wear 
  index. 
  
  If anyone would like to see another model included, speak up. Thanks to Joel
  we have enough raw data to calculate even the obscure stuff like Breadloaf 
  buses with 1600s and "mountain gears"
  
  

                           VW Bus Relative Wear Index
                           
                           
                           
    Year | Top Gear  |  Final Drive | Engine Revs | Stroke | Piston Travel  
         |  Ratio    |   Ratio      |   /Mile 	  |        |     /Mile
   ________________________________________________________________________
  Micro  |           |              |             |        |
  1200   |    0.82   | 4.125 x 1.39 |   3719      |  64mm  |   1571 ft.
  Micro  |           |              |             |        |
  1500   |    0.82   | 4.125 x 1.26 |   3371      |  69mm  |   1525 ft.
  Micro  |           |              |             |        |
  1 ton  |    0.82   | 4.375 x 1.26 |   3575      |  69mm  |   1618 ft.
         |           |              |             |        |   
   68-71 |    0.82   |   5.375:1    |   3484      |  69mm  |   1577 ft.            
 72-73.5 |    0.82   |   5.375:1    |   3484      |  66mm  |   1509 ft.      
  73.5** |    0.89   |   5.375:1    |   3781      |  66mm  |   1637 ft.  
  74-75  |    0.89   |   4.857:1    |   3416      |  66mm  |   1479 ft. 
  76-79  |    0.82   |   4.857:1    |   3181      |  71mm  |   1481 ft.
  79-82  |    0.85   |   4.570:1    |   3072      |  71mm  |   1431 ft.
  Dsl/4  |    0.85   |   5.428:1    |   3650      | 86.4mm |   2069 ft.
  Dsl/5  |    0.77   |   5.428:1    |   3306      | 86.4mm |   1874 ft.
  83-85  |    0.85   |   4.830:1    |   3267      |  69mm  |   1479 ft.
  86-91  |    0.85   |   4.830:1    |   3267      |  76mm  |   1629 ft.   
 Syncro  |    0.85   |   5.428:1    |   3650      |  76mm  |   1820 ft.
Auto. 1.9|    1.00   |   4.090:1    |   3235      |  69mm  |   1464 ft. *
Auto. 2.1|    1.00   |   4.090:1    |   3235      |  76mm  |   1613 ft. *
EV 5 cyl.|    0.76   |   4.610:1    |   2743      | 95.5mm |   1719 ft.
EV 4 cyl.|    0.76   |   4.940:1    |   2939      | 95.5mm |   1841 ft.
79-82 w/ |           |              |             |        |           
<=2.2 911|    0.85   |   4.570:1    |   3072      |  66mm  |   1330 ft   
79-82 w/ |           |              |             |        |           
2.4,7 911|    0.85   |   4.570:1    |   3072      | 70.4mm |   1419 ft   
  
  ** From chassis # 2x3 2068 548
  *  These numbers should be increased by 5-10% due to torque converter slip
  
  
  
  
  
  
  Dave Kautz
  dkautz@hpsidms1.sid.hp.com