Larger tyre size divided x standard tyre size
35” divided by 31” = 1.1290 which = 12%

To calculate correct ratio – Standard diff size x 12%
example – 4.11 x 12% + = 4.6032

The diff ratio required is whatever closest is available to 4.6

Standard diff ratio’s

Landcruiser 40 = 4.11
Landcruiser 60 = 4.11
Landcruiser 70 & 75 = 4.11
Landcruiser 78 manual R151F (split transfer case) = 4.3
Landcruiser 78 manual H150F = 4.10
Landcruiser 80 manual & auto = 4.10
Landcruiser 100 manual = 4.3
Landcruiser 100 auto = 3.9

Hilux diesel = 4.88 Hilux petrol = 4.5

Factory Nissan Patrol Ratios

GQ 2.8 Diesel = 4.625:1
GQ 3.0 Petrol = 4.11:1
GQ 4.2 Petrol auto = 3.9:1
GQ 4.2 Petrol manual = 4.11:1 or 3.9:1
GQ 4.2 Diesel = 4.11:1

GU 2.8 Diesel = 4.625:1
GU 3.0 Turbo diesel auto = 4.375:1
GU 3.0 Turbo diesel manual= 4.11:1
GU 4.2 Diesel = 4.11:1
GU 4.2 Turbo diesel (wagon) = 3.9:1
GU 4.2 Turbo diesel (ute) = 4.11:1
GU 4.5 Petrol = 4.11:1
GU 4.8 Petrol manual = 4.375:1
GU 4.8 Petrol auto = 3.54:1

Please check you compliance plate – example below

• HG41 = 4.11:1 – H233 Front & Rear
• HH41 = 4.11:1 – H233 Front & H260 Rear