Wheel-nut torque

[Whitmarsh]

As a matter of curiosity, can anyone tell me why the wheel-nut torque on the MS is so high - 129 lb ft (175Nm)? Cars I have dealt with over the years have all required about 70 - 80 lb ft. My wrench does go high enough but I don't know whether I could push it that far (or, more to the point, undo the nuts); good thing one will not have to do it at the roadside! I wonder whether most tyre shops do them up tight enough - they seem to have their guns at a single setting that they use all the time.

 

[Johan]

It likely has to do with the agressiv torque available from a standstill and the weight of the vehicle.

175 Nm is more than most cars, but you won't have trouble undoing a 175 Nm lug nut manually, I can guarantee that. If you have a wrench that extends 35 cm from the nut (normal tire wrench) you'd need to apply the equivalent force of 50 kg - not too hard for most people. If you have a slightly longer wrench the force needed will of course be smaller.

 

[jerry33]

The Corvette has a similar torque, so it's not uncommon for very high performance cars. After 100 miles or so of driving the wheels should be re-torqued, so that would take care of any problems.

Note that it is easy to remove the nuts with a breaker bar, requires almost no force.

 

[MrBravo]

You might find this thread interesting: IMPORTANT: New Model S torque specification for mounting wheels

 

[Whitmarsh]

You might find this thread interesting: IMPORTANT: New Model S torque specification for mounting wheels

Yes, thank you, I did. It seems that, apart from the torque that the motors produce and the car's weight, the stud size (14x1.5) and the surface area of mating face are pertinent.

Thank you, everyone who responded.