Mph per 1000 rpm against tyres and overall gear ratios

  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 !!!
N.B.
To estimate for your own vehicle, download actual spreadsheet and insert new row Compiled by Clive Harman Smith 12-11-02

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