ML320 Crawl Ratio

A crawl ratio is calculated by multiplying the following gear ratios:

transmission first gear

transfer case low range

axle differential

torque converter **

  Crawl ratio and low range graph

Crawl ratio (at take off) for the ML320 is 3.932 x 2.64 x 3.7 x 1.85** = 71 :1

This is one of the best crawl ratios in the industry.

The higher
a crawl ratio is the slower a SUV can drive.

The higher a crawl ratio is the more torque is available at the tires.

Extreme slow speeds are essential for delicate maneuvers.

The engine has to complete almost 71 rounds to make the wheels turn only once.


Think of a mountain bike: You pedal a lot - the bike is barely moving.

By using low gears your "one-man-power" is boosted.


Same thing in a 4WD:

Combining all available low gears (crawl ratio) the engine's torque is multiplied by that ratio.

In first gear low range the ML320's torque of 232 lbs/ft is boosted by the factor 71!!


The selected tire size determines the finally available torque.

Taller tires influence the crawl ratio negatively - smaller tires boost the crawl ratio.


**(only to be used to calculate crawl ratio before stall speed is reached )