Auto gear selection for towing.

[Mudnut]

After completing some small trips, I got to wondering what should I do with the auto transmission. I have never towed a heavy load with an auto before. In my TD5 Defender, I did not use 5th gear when towing unless going down a slight grade, and there was no stress on the transmission. Do people use manual mode, and not cruise in 8th? Want to preserve this transmission, and the vehicle for a long time. I do plan on using manual mode for steep downhill grades, to preserve the brakes, even with a braked trailer.

 

[Eric]

After completing some small trips, I got to wondering what should I do with the auto transmission. I have never towed a heavy load with an auto before. In my TD5 Defender, I did not use 5th gear when towing unless going down a slight grade, and there was no stress on the transmission. Do people use manual mode, and not cruise in 8th? Want to preserve this transmission, and the vehicle for a long time. I do plan on using manual mode for steep downhill grades, to preserve the brakes, even with a braked trailer.

Have towed heavy loads (3.5 T ) occasionally for decades in an auto. 5 number auto L/R Discoverys before the Grenadier. In that time of ownership of I have never used the manual functionality. The Grenadier pulls and tows better than the L/R. You are using the same gearbox whether it is auto or manual mode and the torque in the gearbox will be the same. For going down very steep hills you can always use the downhill assist function.

 

[Jeremy996]

Let the auto make the decisions! (unless you are going downhill and need engine braking or similar).

The manufacturer has gone to a lot of trouble to optimise the gearing and the shift points for towing and normal driving, so for the vast majority of the time the truck will be able to make a decision at least as good as the one you would make. Where this comes unstuck is situations where the truck does not know the lie of the land or the friction coefficient of the ground surface. Here you would be advised to make a decision for the truck!

(As a general rule, automated systems make a poor driver at least average; a truly excellent driver might find the automated systems a bit of a drawback, but the vast majority of drivers are less than really excellent). ABS is a good example; the very best drivers can out-brake an ABS equipped vehicle in a vehicle not equipped with ABS, BUT drivers that good are very, very rare and ABS makes a suitably equipped vehicle at least consistent for most drivers.