Model S Trailer Hitch Installation

[Jasper7821]

The new ecohitch arrived! Here are the pics.

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Wow, that looks pretty stout. Very nice, looking forward to mine. I
’m going to need the larger capacity, I put a deposit on the larger boat today not the smaller one. Looking forward to enjoying the summer and taking my car and not have to pay for gas to go to the lake.

 

[dmwahl]

Very nice, is the long tube all one piece or is it 2 pieces welded to the center drop? Stainless steel? Of course now you're on the hook for even more installation pictures (please )

 

[jjvan]

Very nice, is the long tube all one piece or is it 2 pieces welded to the center drop? Stainless steel? Of course now you're on the hook for even more installation pictures (please )

The cross tube is still two pieces but the tubing is thicker and the welds look pretty heavy duty. The receiver has “stainless” stamped into it but all the tubing is painted and difficult to tell if it is actually stainless. I’ll for sure take some installation photos. Here are some additional photos.

 

[Jasper7821]

I can add a data point for towing with my Y. Two LARGE jet skis on a trailer wider than my car and total weight of about 3300 lbs cut my range in half at 55 mph. It was whacked by about 65-70% when going 70 mph.

It had no problem towing at pretty much any speed I wanted with a lot less power than the S has. Even towing the trailer I could probably do 0-60 in the high 5 second range. Absolutely no issue going up steep and wet boat ramps.

Getting a different boat, the original one they missed measured and it was 6 inches too long to fit into the garage. So I went today to look at one and I’m going back tomorrow to pick it up.
We did a little driving to test it out in my car, and at 70mph it was pulling about 800 watts, and at 60mph it was pulling about
700 watts.

On the drive there I measured and was averaging 280 watts at 65mph, and just over 300 watts at 70mph.
And this boat is smaller and lighter than the original one.
This one is about 2k total.

One thing to note, I only pulled it around less than 10 miles but to get home I had to go to the supercharger in I drove about 10 miles without the boat to the supercharger and I think it still had some of that weight calculated. Because I charge it to where it’s at 15% to get home and as I drove the percentage kept going up to 21% and that’s going 82 miles an hour. So I guess I stay too long in the supercharger

 

[roblab]

I've had a hitch on mine for years. Hardly ever use it, but when you need one, you NEED one. Mostly use a small aluminum trailer to haul junk to the dump. I also towed my three wheeled bike on its trailer for a while until I sold it. Gettin' too old to enjoy riding down Napa Valley anymore.

 

[Jasper7821]

Even though it said 800 watts at 70mph and 700 watts at 60mph in Scan My Tesla, the trip meter for the 10 miles I pulled the boat only said 650 watts.
On the drive from the supercharger back to the guys house, the trip meter said 335 watts.
So for those two trips driving around with and without the boat, the car said it was double the usage pulling the boat.

Going back to Phoenix today to pick it up, we’ll see how it does on the 150 mile drive home.

On a side note, I got to his house with only not enough battery to pull the boat around to see how the car would handle it. I went 10 miles to the Deer Valley supercharger and it charged like it normally does. With that % of battery left it averaged about 70kw.
But after pulling the boat around, I left his house and and went back to the same supercharger to charge enough to her home. When I plugged in at about 14%, I was only getting 18-20kw. I tried two other stations and same thing. I had to stay there for an hour to get enough to get me to the next stop, and the next stop charges normally.
I’m hoping it was just an issue with those superchargers and not something with my car. The cell temps were same at they always are (about 115 degrees) so I don’t think pulling the boat caused any issue.

Oh well, have to see what today’s adventure bringing the boat home goes like.

 

[Jasper7821]

When I purchased my Model S 85 D just over a year ago one of the big concessions I made when purchasing it was giving up my ability to tow trailers or use my trailer hitch bike rack. I knew there was an aftermarket trailer hitch option, but I was a little scared to take my Tesla apart, and I didn’t want to pay lots of money for someone else to do it. After researching it more I decided to take the plunge and DIY it. I had some great friends come help me which was helpful and I was able to make a video of how to do it. I found a couple other installation videos on YouTube for the Model S, but it was for the newer Model S. After hours of searching I found zero instructions on how to do the trailer wiring in my Model S! I hope this empowers others to be able to DIY the installation because it turned out to not be overly difficult in my opinion. I’ve now had it installed for nearly 3 months and I’ve loved the functionality it provides!

In my case I also installed trailer light wiring (which was a lot more difficult to figure out, but I succeeded!) and now I’ve been able to take our small 14 foot fishing boat to multiple lakes, I’ve towed a small camping trailer, small utility trailer, large utility trailer and used our trailer hitch bike rack. I highly recommend doing it if you’ve ever thought it would be useful functionality to have. Feel free to ask any questions you may have and I’ll do the best I can to answer them based on my experience.

This is a video I created on the why, parts and costs associated with the installation

This is my trailer hitch installation instruction video

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I was having issues with the trailer lights working and I ended up talking to technical support from Tekonsha, I bought the same wiring you have. But they told me the wires different. And the tail and stop light wires are accessible from the right tail light so you don’t have to take the upper trim off.
We’ll see what happens if it works.

They ran my VIN and said that’s the wiring for my 2014 P85+.

Stop dark green with pink stripe right side

Left blinker violet

Right blinker tan with black stripe

Tail light tan with dark blue

 

[Jasper7821]

And the 150 mile journey begins

 

[dmwahl]

And the 150 mile journey begins View attachment 805193

Very interested to hear how this goes. My annual trip with the boat has 135 miles between superchargers and I'm concerned i wouldn't make it even at 100% with 2900lbs of boat.

 

[ThomasD]

How was your trip ? Hope you made it home safe?

 

[Jasper7821]

How was your trip ? Hope you made it home safe?

Home safe, BUT, it took a while.

 

[Jasper7821]

Very interested to hear how this goes. My annual trip with the boat has 135 miles between superchargers and I'm concerned i wouldn't make it even at 100% with 2900lbs of boat.

With 130 miles between stations, I don't think you'll make it. My car when charged to 100% says about 240 miles, but you'd never get that unless driving 40-50mph in town.
Antyways, the boat and trailer is about 2k and at 65mph on the freeway it was averaging 650 watts per mile. It's uphill from Phoenix to Tucson (about 1,200ft) so it may be a little better going the other way (will find out when I take the boat to the lake).

You cannot rely on the car's trip calculator. I thought in the 10 miles from where I bought the boat to the Supercharger, it would calculate for the weight. It did, but not very accurately to 87% and the next Supercharger was 70 miles away and it said I'd get there with 47%.
I drive 65mph and got there with 20%. So it calculated with the extra weight somewhat.

At the next Supercharger I charged to 69% and it said I'd have 29% when I got home (another 70 miles). There is a Supercharger at my exit right after the freeway , then it's 10 miles to my house on streets. it kept saying less and less % left to get home. I slowed to 60mph and it hung saying 14% for a bit then it was going down again. I ended up getting home with 5%.

So it seem to be about 65% to go 70 miles with going 60-65 mph, not good at all. But with a 2014 S, it is what it is,
And it was an hour charging at the first stop and 45 minutes at the 2nd.
So for taking a road trip a few hundred miles towing a boat with the old Model S isn't very fun, but I guess it's at least not paying for gas.
The guy I bought the boat from texted me a photo and said his boat detailer saw me on the freeway, and he texted me a photo. Pretty funny.

 

[DayTrippin]

Use ABRP - a better route planner. You can factor in a trailer, roof rack, etc. quite easily. You set up an alternative configuration of your car. It can pull real-time data from your car and tell you what speed you need to drive at current conditions if you need to slow down to make it to a charger. I used it all the time when towing with my Y if going more than about 50 miles from home.

 

[Jasper7821]

Use ABRP - a better route planner. You can factor in a trailer, roof rack, etc. quite easily. You set up an alternative configuration of your car. It can pull real-time data from your car and tell you what speed you need to drive at current conditions if you need to slow down to make it to a charger. I used it all the time when towing with my Y if going more than about 50 miles from home.

I did use it calculating all different wattages last week. For some dumb reason, I totally forgot about it. Maybe the excitement of getting a boat did it . But I just ran the numbers again at 650 watts and it’s fairly accurate.
Except it says almost exactly the percentages I did but I had to drive 60mph to get home, and ABRP says 65.
For the 1/2, it was accurate, just the 2nd half it was off by 5mph.

At least now I can pretty accurately calculate the percentages I need.

This is really not a good car for towing long distance, I think if I go to the lake for the weekend, I’ll take the Tesla, but if I go for a day, I’ll take a friend who has a truck/SUV.

It’s an extra 2hrs 10 minutes charging and maybe another 20 minutes driving at 65 verses if in a truck I’d maybe do 70-75.

So for an extra 5hrs just to have a free ride, instead of about $75 round trip in gas doesn’t really make it worth it.

Plus there’s also whatever watts it’s going to take leaving the car in parking lot in the 115 degree heat all day.
Unless I turn off overheat protection, but don’t know if that’ll damage anything in the car like the screen glue/gel.

 

[DayTrippin]

As you get more data, fine-tune the inputs on ABRP. It will get better as you dial it in. Do you use the free version? The paid has more customization. Took me a bit of time to learn the interface. After I dialed in my 2 different trailers I pulled, it was easy to pull up the config I needed to optimize my routes.

Anyway, congrats on the new boat!

 

[Jasper7821]

As you get more data, fine-tune the inputs on ABRP. It will get better as you dial it in. Do you use the free version? The paid has more customization. Took me a bit of time to learn the interface. After I dialed in my 2 different trailers I pulled, it was easy to pull up the config I needed to optimize my routes.

Anyway, congrats on the new boat!

Yes I just use the free version, I figured it’s enough to get me fairly accurate results. Only thing I changed is max speed of 65 and put in 650 watts. Heading back to Phoenix will be a 1,300ft down grade overall so should be a few less watts.

But probably going to even worse if I load time car with 4 people and everyone’s stuff in the boat . But I can play with ABRP and add those weights to see how much worse it’ll get.

 

[DayTrippin]

I think the paid one allows more customization and things like realtime weather. While I don't use the app all the time, I figure a few bucks a month to help the developer is worth it.

I would encourage putting the weight you can more in the car than the boat. I've found it to be less of an effect on the efficiency. Also spend time to optimize the boat on the trailer. You can adjust the rollers and bunks and maybe improve the efficiency a bit more if you have room to lower. See if you can drop the Bimini top a boat when driving. That is at least a few % there.

Also a boat cover (for towing) can help out as well. Of course trailer tire pressure is something to check. Don't fuel the boat up until close to your destination as well if you can.

 

[Jasper7821]

I think the paid one allows more customization and things like realtime weather. While I don't use the app all the time, I figure a few bucks a month to help the developer is worth it.

I would encourage putting the weight you can more in the car than the boat. I've found it to be less of an effect on the efficiency. Also spend time to optimize the boat on the trailer. You can adjust the rollers and bunks and maybe improve the efficiency a bit more if you have room to lower. See if you can drop the Bimini top a boat when driving. That is at least a few % there.

Also a boat cover (for towing) can help out as well. Of course trailer tire pressure is something to check. Don't fuel the boat up until close to your destination as well if you can.

Thank you, another thing I don’t think ABRP isn’t calculating is the time to charge. Since my old S charges much slower as it fills than newer cars, it seems to be off by about 10-15 minutes charging each time I’ve driven to California l. So I have to add time accordingly to get a more realistic overall time increase over a gas truck.

And this trip I had nothing, I picked up the boat by myself. But I added extra weight for ABRP for passengers and stuff on future trips.

And nothing in the boat can be adjusted as far as I know like lowering the bunks or anything
The Bimini has 3 settings, fully open, a higher storage position then one than I had, and the one I had. What I should have done is pulled the pins and had the top just lying on the seats. I’m sure that would’ve saved a little drag.

It did come with a custom made trailering cover made for that specific boat. I was in hurry and didn’t put it on. The owner said it’s pretty form fitting and it fits with the Bimini in the position I had it in. I still think that would have been less drag.
I’ll use it next time and see the avg watts.

The fuel tank is small (13gal) and it was 1/2 full, so it was only about 40lbs.

And I never checked the tire pressure on the trailer, I even forgot the spare tire in his garage. He lives by the lake I’d be going to, so he’s going to meet me at the supercharger when I go.

I usually have my 21” tires at about 42F/44R cold. They were running about 46/47 on the freeway, I don’t know if that’s most efficient or not.

Thank you for the advice, I think I’ll try to get there this weekend and stay the night so I can have two lake days to make it worth the 4.5hrs extra from charging and driving 65mph.

 

[DayTrippin]

A lot of little things put together can make significant gains. A percent here and there and it can add up to real gains fairly quickly. The best thing is most of these are free to do.

As for the trailer roller and bunks, sometimes they are adjustable. Might not be worth the hassle though if you can't move it at least an inch. The boat cover would be a lot more useful. I would also get a transom support rod. You could then have the motor tilted up a big, less drag than the prop hanging down. You don't want to trailer with the motor up and using power tilt on it as it is extra stress on the transom without a support bar. Also with the motor up, less chance of grounding it out and breaking the keg on the lower unit or damaging the prop.

 

[Jasper7821]

A lot of little things put together can make significant gains. A percent here and there and it can add up to real gains fairly quickly. The best thing is most of these are free to do.

As for the trailer roller and bunks, sometimes they are adjustable. Might not be worth the hassle though if you can't move it at least an inch. The boat cover would be a lot more useful. I would also get a transom support rod. You could then have the motor tilted up a big, less drag than the prop hanging down. You don't want to trailer with the motor up and using power tilt on it as it is extra stress on the transom without a support bar. Also with the motor up, less chance of grounding it out and breaking the keg on the lower unit or damaging the prop.

I’ll have to to a test run on the freeway with the cover on and see what the difference is.
It does have a support rod already. It only has one position, and I think with the cover on, it’s not going to matter what position the motor is in cause with the Bimini in the position it’s in now (owner said that’s the position with the cover on), it looks like it’ll cover the motor anyways.

These are the best photos that show the motor height resting on the transom support rod.

If I have time, I’ll put the cover on this evening and see what it looks like.