| Overall gear ratio in top | |||||||||||
| Lock? | 3.904761905 | 4.148809524 | 4.234285714 | 4.55 | 4.636904762 | 5.267361111 | 3.565714286 | ||||
| Rolling tyre circumferences/ Revolutions per mile | Y | AKG | AAN/AAM/AVN | AHF/AVK | AHA/AVM/AVS | 6PA/6ZA/ALK/AVR/AVL | AND/AVU | Highest gear combo | |||
|
Comment
|
Roll. circ. (m) | Roll. circ. (ft) | Revs/mile | N | AKE | AVV/AVL | AGZ/AVJ | AVF/AKK | 6P/6Z/AVH | ||
| Miles per Hour per 1000 RPM | |||||||||||
| 1.500000 | 4.921260 | 1072.90 | 14.321848 | 13.479387 | 13.207282 | 12.290859 | 12.060504 | 10.616969 | 15.683648 | ||
| 1.600000 | 5.249344 | 1005.84 | 15.276638 | 14.378012 | 14.087768 | 13.110249 | 12.864537 | 11.324766 | 16.729224 | ||
| 1.700000 | 5.577428 | 946.67 | 16.231428 | 15.276638 | 14.968253 | 13.929640 | 13.668571 | 12.032564 | 17.774801 | ||
| 1.800000 | 5.905512 | 894.08 | 17.186218 | 16.175264 | 15.848739 | 14.749030 | 14.472605 | 12.740362 | 18.820377 | ||
| 1.850000 | 6.069554 | 869.92 | 17.663613 | 16.624577 | 16.288982 | 15.158726 | 14.874621 | 13.094261 | 19.343166 | ||
|
14" Typ?
|
2.000000 | 6.561680 | 804.67 | 19.095798 | 17.972515 | 17.609710 | 16.387812 | 16.080672 | 14.155958 | 20.911531 | |
| 2.050000 | 6.725722 | 785.05 | 19.573193 | 18.421828 | 18.049953 | 16.797507 | 16.482688 | 14.509857 | 21.434319 | ||
| 2.100000 | 6.889764 | 766.35 | 20.050587 | 18.871141 | 18.490195 | 17.207202 | 16.884705 | 14.863756 | 21.957107 | ||
| 2.150000 | 7.053806 | 748.53 | 20.527982 | 19.320454 | 18.930438 | 17.616898 | 17.286722 | 15.217655 | 22.479895 | ||
| 2.200000 | 7.217848 | 731.52 | 21.005377 | 19.769767 | 19.370681 | 18.026593 | 17.688739 | 15.571554 | 23.002684 | ||
|
Kumho 195/15 (TRC Calculator)
|
2.114000 | 6.935696 | 761.28 | 20.184258 | 18.996949 | 18.613463 | 17.321917 | 16.997270 | 14.962848 | 22.103488 | |
|
'' '' (Height meas.)
|
2.201580 | 7.223031 | 731.00 | 21.020463 | 19.783965 | 19.384593 | 18.039539 | 17.701443 | 15.582737 | 23.019204 | |
| 2.250000 | 7.381890 | 715.26 | 21.482772 | 20.219080 | 19.810924 | 18.436288 | 18.090756 | 15.925453 | 23.525472 | ||
| 2.300000 | 7.545932 | 699.71 | 21.960167 | 20.668393 | 20.251166 | 18.845983 | 18.492772 | 16.279352 | 24.048260 | ||
| 2.350000 | 7.709974 | 684.83 | 22.437562 | 21.117706 | 20.691409 | 19.255679 | 18.894789 | 16.633251 | 24.571048 | ||
|
16" 'Big' tyre estimate
|
2.366680 | 7.764698 | 680.00 | 22.596821 | 21.267596 | 20.838274 | 19.392353 | 19.028902 | 16.751311 | 24.745451 | |
|
245/75/16 (Alfisti.net)
|
2.360000 | 7.742782 | 681.93 | 22.533041 | 21.207568 | 20.779458 | 19.337618 | 18.975193 | 16.704031 | 24.675606 | |
| 2.400000 | 7.874016 | 670.56 | 22.914957 | 21.567018 | 21.131652 | 19.665374 | 19.296806 | 16.987150 | 25.093837 | ||
| 2.450000 | 8.038058 | 656.88 | 23.392352 | 22.016331 | 21.571895 | 20.075069 | 19.698823 | 17.341049 | 25.616625 | ||
| 2.500000 | 8.202100 | 643.74 | 23.869747 | 22.465644 | 22.012137 | 20.484765 | 20.100840 | 17.694948 | 26.139413 | ||
| Help with estimation/ calculation/ true measurement of tyre dynamic rolling circumference/ revs per mile | |||||||||||
| Michelin MXLs (819 revs per mile) that came on the vehicle new in the 80s (14") | |||||||||||
| BF Goodrich 27x8.50/14 (782 revs per mile) | |||||||||||
| Big 16" Tyre 245/75/16 (rated 30.5" tall; 680 revs per mile) | |||||||||||
| NB. Some 29.5" tall tyres might actually achieve 680 revs per mile | |||||||||||
| NB. Generally a manufacturers rated revs per mile will equate to a lower tire height than quoted (of course) - i.e. large errors can be incurred using tire height as rolling diameter. | |||||||||||
| Below is a rolling radius and circumference calculator - it is accuarte enough for a first approximation | |||||||||||
| TRC Calculator | |||||||||||
| Ideally - mark the ground & tyre, drive while counting say 10 revolutions of wheel exactly and measure the distance (use smooth flat surface). | |||||||||||
| NB. It would be unwise to exceed 20mph/1000 rpm in a Transporter unless you have 150 - 200 BHp at the flywheel !!! | |||||||||||
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N.B.
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To estimate for your own vehicle, download actual spreadsheet and insert new row | Compiled by Clive Harman Smith 12-11-02 | |||||||||