The Model X is capable of towing up to 5000 pounds with 500 pounds of tongue weight (19-20" wheels). When considering towing anything more than half of that maximum, the subject of WD (weight distribution) hitches comes up. I've seen a number of rules of thumb, but generally what I see is that if the TT (travel trailer) is more than 50% of the TV (towing vehicle)'s weight, a WD hitch is recommended. The Model X weighs ~5300 lbs, so any trailer over 2650 lbs would qualify.
First, it will be helpful to describe a typical (non-WD) towing configuration. The Model X has two axles on the ground, and the travel trailer, for ease of discussion, has a single axle on the ground. The two vehicles are connected solely by the ball hitch and safety chains. The tongue weight is the weight pushing downward on the ball hitch at rest. That weight pushes downward on the back of the Model X, and therefore pushes down the back axle while taking weight off of the front axle. As the tongue weight increases, this scenario can create instability in the form of lack of maneuverability. It can also create a situation where the trailer tilts downward at the front significantly, with the towing vehicle tipping downward at the rear and upward at the front. A tiny amount of trailer front-tilt is desired for stability reasons, but too much will also cause issues.
Weighting the trailer behind the axles can alleviate some of this and balance the load. However, too much in the back and the trailer will tilt backward. From what I understand, this is the most unstable configuration, as air under the trailer can cause lift and sway.
In comes the WD hitch. The best description I've read is that this is like standing on the front of the trailer and lifting upward on a stiff pipe inserted into the receiver on the towing vehicle. What happens when you do that is that you take weight off of the rear axle of the tow vehicle, and distribute that weight between the trailer axle and the front axle of the towing vehicle. In doing so, you create a bit of vertical plane rigidity between the two, and they act almost as one single mass.
So, that's good enough and makes plenty of sense, except my online research shows that there are some problems with this. One problem is that the Model X has a unitary body construction, and there are varying opinions on whether or not WD hitches are appropriate for that style of frame. If you imagine that rigid rod going through the receiver, and remember that it's also square, you can imagine the torque that is placed on the hitch and the vehicle whenever the road is not similar for the trailer axles and the vehicle axles. A bumpy road will transfer a lot of stress into the unibody of the Model X. The reason that's considered detrimental is that the entire body will bend and twist repeatedly, and could eventually fail. Opinions vary on whether or not this is a serious problem, and I can find no empirical data one way or the other. Tesla's use of aluminum in lieu of steel is also a big question mark in this realm.
Another problem appears to be the auto-leveling mechanism built into the Model X. This is set up so that when you attach a tow vehicle, the air suspension levels the X for you. Similar products from Mercedes and BMW suggest completely disabling this when a weight distribution hitch is attached, and most manufacturers of unibody vehicles suggest against using a WD hitch at all.
Where does that leave us? On one hand, the literature says that a travel trailer approaching more than half of our vehicle weight should use a weight distribution hitch for safety and stability. On the other hand, there is advice against it because of the unibody construction and air suspension of the X.
Are there any knowledgeable opinions on this?
*Also, any corrections to erroneous statements I've made are welcome.
First, it will be helpful to describe a typical (non-WD) towing configuration. The Model X has two axles on the ground, and the travel trailer, for ease of discussion, has a single axle on the ground. The two vehicles are connected solely by the ball hitch and safety chains. The tongue weight is the weight pushing downward on the ball hitch at rest. That weight pushes downward on the back of the Model X, and therefore pushes down the back axle while taking weight off of the front axle. As the tongue weight increases, this scenario can create instability in the form of lack of maneuverability. It can also create a situation where the trailer tilts downward at the front significantly, with the towing vehicle tipping downward at the rear and upward at the front. A tiny amount of trailer front-tilt is desired for stability reasons, but too much will also cause issues.
Weighting the trailer behind the axles can alleviate some of this and balance the load. However, too much in the back and the trailer will tilt backward. From what I understand, this is the most unstable configuration, as air under the trailer can cause lift and sway.
In comes the WD hitch. The best description I've read is that this is like standing on the front of the trailer and lifting upward on a stiff pipe inserted into the receiver on the towing vehicle. What happens when you do that is that you take weight off of the rear axle of the tow vehicle, and distribute that weight between the trailer axle and the front axle of the towing vehicle. In doing so, you create a bit of vertical plane rigidity between the two, and they act almost as one single mass.
So, that's good enough and makes plenty of sense, except my online research shows that there are some problems with this. One problem is that the Model X has a unitary body construction, and there are varying opinions on whether or not WD hitches are appropriate for that style of frame. If you imagine that rigid rod going through the receiver, and remember that it's also square, you can imagine the torque that is placed on the hitch and the vehicle whenever the road is not similar for the trailer axles and the vehicle axles. A bumpy road will transfer a lot of stress into the unibody of the Model X. The reason that's considered detrimental is that the entire body will bend and twist repeatedly, and could eventually fail. Opinions vary on whether or not this is a serious problem, and I can find no empirical data one way or the other. Tesla's use of aluminum in lieu of steel is also a big question mark in this realm.
Another problem appears to be the auto-leveling mechanism built into the Model X. This is set up so that when you attach a tow vehicle, the air suspension levels the X for you. Similar products from Mercedes and BMW suggest completely disabling this when a weight distribution hitch is attached, and most manufacturers of unibody vehicles suggest against using a WD hitch at all.
Where does that leave us? On one hand, the literature says that a travel trailer approaching more than half of our vehicle weight should use a weight distribution hitch for safety and stability. On the other hand, there is advice against it because of the unibody construction and air suspension of the X.
Are there any knowledgeable opinions on this?
*Also, any corrections to erroneous statements I've made are welcome.
