Hitch Installation & Impact on Range, Updated 10/15/13

Hitch Installation & Impact on Range, Updated 10/15/13

We installed a Torklift hitch system on our Model S and took pictures documenting the installation, mounting a Saris Thelma hitch rack and Trek road bicycle, including the underbody and disassembled rear of the car. The pictures also include some shots of the barn with solar panel installation:

The Torklift hitch is a custom hitch for the Model S, available with two adapter - 1.5" and 2". It has detailed instructions on how to remove the rear bodywork, bottom panels, and bumper crossbars to install the hitch receiver. The system installs without structural drilling, using existing bolts and nuts that are part of the Tesla bumper system.

Installation is complex, and for most people should be done in a body shop. However, we have a lift in the barn and all the needed tools, so I tackled it myself.

Immediately inside the bumper cover is a stamped steel bumper cross member that is attached with eight nuts, onto studs that protrude from the aluminum body. This steel cross member covers an extruded aluminum reinforcement that is the main structural element inside the rear bumper, providing crash protection for rear-facing passengers in the jump seat (in cars so equipped).

The instructions are to remove the eight nuts holdng the steel cross member with a 17mm socket wrench, then remove eight more nuts that attach the aluminum crossbar, using a 15mm socket wrench. The trailer hitch is then mounted behind (forward on the car) both crossbars using the original nuts to hold all three crosspieces (including the new hitch) in place.

As I outlined in a separate post, we uncovered loose nuts for the steel bumper liner. The linked pictures include several that show a quality control issue when assembling my car. Three of the four nuts holding the right side of the steel bumper crossmember were barely threaded onto their respective studs. They were not even hand tight, but just started onto the studs, far away fom being seated. The fourth nut was properly torqued to 40 ft. lbs. (the torque recommended in the hitch instructions).

I seated and torqued the nuts upon installing the hitch, so no harm in our case, but it is in an area that cannot be inspected without major dissassembly, and it does make one wonder what else wasn't tightenned on this or other cars.... This issue is discussed fully in the other link, so no more about it here.

Returning to the hitch installation, there is a video on the manufacturer's website:

A small fitment issue required minor grinding on the hitch, and the two stud extenders were about 1/4" too long, so I trimmed them with a Dremmel cut-off wheel. Pictures of this are in the Dropbox link. Installation also requires cutting a pretty big hole in the bottom rear body cover, including the forward part of the plastic chrome finisher at the bottom of the bumper. The provided template suggests using a 4" hole saw on both ends of the oblong hole to get it started. I do not have a hole saw that big, so masked the surface to protect the paint and chrome, and transferred the template to the tape, drilled a starter hole, and used a jig saw to do the job. Cutting the bumper cover was the scariest part of the job.

The hitch worked great but does reduce battery range. Last night we drove 170 miles with it and a bike on a hitch rack. We began with a full max range charge (272 rated at start) and drove normally, Mostly 65 mph, some 75. We had 10 miles left on arrival, so lost about 90 miles of rated range due to a combination of low temperatures, slightly above average speed, and the rear rack. The hitch/rack/bike combo seemed to affect range about 10-15%, as we averaged 404 kwh, and normally average 340-350 on that trip at those temps (about 40 degrees) and speeds. However, we did have the headlights on as it was dark the entire way, and all of our prior trips over this route were with the lights off during the day.

Driving with the bike carrier and two road bikes are akin to pulling a parachute behind a vehicle designed for least air resistance. We did this because regular strap-on bike carriers can't be used with the aluminum body, and since the car is designed with specific attachment points for a roof rack, Tesla must have testing saying exterior wind disruption isn't terribly bad. I figure that a rear hitch mounted rack is less disruptive than having two bikes mounted on the roof.

Since we had almost no range cushion with a max range charge for this trip, I am further reducing range planning allowance for this car. We now think of the 85 kwh Model S as a 175 mile range car for normal trip planning, but 155-160 with the bikes on the hitch rack.
10-15-2013 UPDATE

We have used the hitch a number times of since since the original post above and have the following updated observations:

1) Quality - the hitch has performed flawlessly for both the bicycle rack and to tow a small utility trailer. We originally bought the 2" receiver adapter and later added the 1.25" receiver, which is a lot lighter and less bulky. We have had no quality issues with the hitch and good service response from the manufacturer.

2) Impact on warranty - We limit towing to under 1,000 pounds, as the car does not have a trailer rating. Most of our trips have been with just the Saris bike rack, but twice we have pulled an 8' utility trailer loaded with an ATV, about 60 miles each way to a servicing dealer. We also use it often to make 20-mile runs to the dump from our farm (we have no trash pickup in the boonies). One time we used it to tow a dual-jet ski trailer for three miles to a boat ramp, on flat roads. Basically, we limit its use to lightweight trailers that do not need or have onboard brakes. TM seems to tacitly approve of the hitch, as they provided space for presentation as Teslive and other Model S events. My car has been serviced several times since installation, and the service center techs commented on the high quality of the hitch. Although lawyers may worry more about fine print, I see nothing that towing light loads could do to damage the car, and it seems logical that prudent use will not affect warranty coverage.

3) Impact on range - this is the unhappy side of doing anything to the Model S low-profile envelope. We generally use about 290 -300 wh/mi driving the "bare" car with two occupants and a medium size dog between our houses, over mostly flat roads, 190 miles each way. In lower temperatures this climbs to about 335 wh/mi. Our average since new is 325 wh/mi, including all miles driven, with lots of full-out test drives. Unfortunately, putting the Saris Thelma bike rack on the hitch receiver, with two carbon fiber road bicycles, pushes the wh/mi up to 425-430 at 55-65 mph, under identical conditions, or about 125 wh/mi, reducing range by 28%. This cuts range on a full max range charge to below 190. The loaded bike rack is essentially like pulling a parachute behind the car. The bikes stick up slightly above the roof line and destroy aerodynamic integrity. The pictures in dropbox show how disruptive the rack and bikes can be.

Our battery charge ran down to zero miles last night at exactly 188.5 miles after a full range charge and driving 55-65 mph in moderate temperatures with no hard acceleration. This says we lose about 74 miles of range due to using the bike rack. This makes it impossible to take the bicycles back and forth between houses in cold weather, and it is risky in moderate temps despite a max charge. The bottom line is that range loss eliminates using the hitch in about 50% of the cases that we would like to employ it. However it does give an excuse to buy two more bicycles for the second house.

Sudre_ | February 17, 2013

Thanks for this post. I have been looking at that hitch for a while and the video just made it look so easy I couldn't believe it.
Has anyone spoke with Tesla about any warranty issues? I really don't see it being a problem... just curious. | February 17, 2013

Thanks for the post-- I am also looking at that hitch for occasional bike transport...

Pungoteague_Dave | February 18, 2013

I have not asked TM about how this would affect the warranty, but don't think it should have any impact. They have a provision already for a roof rack on pano-roof-equipped cars, and installation of the hitch does not affect anything about how the car operates, but does add another steel crossmember at the rear of the car. As noted above, there is no cutting or drilling of any structural part - just a plastic hole in the bumper cover.

However, were I to pull a trailer it could be another story - I doubt the Model S has a tow rating, or that the brakes and stability system is set up to deal with the weight of a trailer back there. That coudl perhaps affect warranty. I would think thatit can pull a small traler with a motorcycle, ATV or jet ski, butI would not do that.

We might put on a small open utility trailer weighing under 500 lbs. for trash runs to the dump (we don't have trash pickup at our farm), but don't think we will as we have farm trucks for that.

Brian H | February 18, 2013

You need a Model X for trash runs! ;)

kw1 | February 19, 2013

nice set of pictures. nice car, nice barn. looks like you have enough solar panels to power a small town. Definitely a green setup. It looks like you have fully embraced the future and have made me think about getting soar panels for my MS.

Pungoteague_Dave | February 19, 2013

We do have green cars, and 112 solar panels, plus 100% LED lighting throughout the farm, and 10 geothermal wells, but without government subsidies none of those things would have happened. Being in the 1%, I find it fascinating that the current government has directly funded so much of my personal lifestyle. None of these benefits (deductions and credits) are available to people of average household income or lower. One person's loophole is another person's definition of investment.

What you see in those pictures is about $450,000 in government payments to my family in the form of renewable energy tax credits, farm grants, and business deductions, most of which were created by the green-focused current administration (although not the $7,500 payment we received to buy the Model S, which was a Bush administration program). I personally have a moral quandary with this given fiscal reality, but if they want to give us money to do stuff, we will do that stuff.

Sudre_ | February 19, 2013

Dave don't give the the moral issue bull. If you had a moral issue with it you could have skipped the deductions and credits. Then again our government would probably audit you and give you the money anyway. That happened to my mom one year. FED audit and the government ended up owing her and extra 2k. They never audited her again. lol.

Brian H | February 19, 2013

Dave's acknowledging that everyone else paid for his upgrades, etc., for purely theoretical benefit. The US could stop emitting CO2 entirely tomorrow, and it would take China, not to mention the rest of the BRIC crew, about 4 months to make up the difference and carry on. Except that their main customer would be no more.

kw1 | February 19, 2013

Dave, A major part of tax policy is to encourage investments in places where the government (i.e. the people of the US) would like the economy to go. We subsidize oil through depletion allowances and all sorts of investment credits. We subsidize research and development of many different of industries. And we have chosen to subsidize renewable energy through tax policy. Until we get to a flat rate tax (which may be either good or bad), then you are not taking advantage of the system. You are in fact doing exactly what the system is hoping you would do. And putting people and companies to work as you do it (someone had to build and install all of that). So thank you, and enjoy.

wonder | April 22, 2013

I have an interest in towing a small light weight "canoe trailer" with a 60 Lb. canoe (as well as bycycle). I spoke with Tesla Configuration Rep. and was told would not impact Warranty. Of course my interest would likely impact range less than one or two adult passengers. I was told the motor would have plenty of torque which makes sense. Specifications show a standard 85 kWh Model S has 362 hp and 325 Lb-ft of torque. The one thing the guy said was be careful when accelerating since there will be no delay ..., direct transfer to trailer. That said you never do know ..., lawyers ..., fine print ..., and all.

jat | April 22, 2013

@wonder - I would expect pulling a trailer will cost you far more than a couple of passengers due to drag.

Brian H | April 23, 2013

yeah, unless the passengers are leaning out the window and playing "airplane"! Could happen ...

wonder | April 26, 2013

Could be! I should have enough range though. Can get to quite a few different local lakes within an hour or so one way. Most if not all will likely have access to RV type 40 amp outlets if I want to go that route maybe for a long weekend. Sure would be nice to have Superchargers between here (St. Louis area) up through Deluth, MN and over to Ely, MN (Boundary Waters Canoe Country).

kilimats | April 26, 2013

If you are only going to use it for bikes, may i suggest a different approach ?

Sudre_ | May 15, 2013

I have a question Dave, if you happen to notice this post.

Is there an electrical harness with the kit for the trailer lights?

I don't plan on pulling a heavy boat but if I get this hitch I might get one of those small utility trailers to pull a kayak, canoe or something very light. After having a roof rack on my Saturn I have no interest making the climb to the roof to get stuff any more.

Pungoteague_Dave | July 25, 2013


Sorry for the delay, we have been in Africa for a couple months. There is no wiring harness from Torklift, but I did add a simple pigtail trailer light harness from

It rides in the rear footwell well and pokes out under the hatch when in use. I will probably only use it a couple times per year. Most of our towing is too heavy (would not pull over 1,000 pounds with the S) - must go behind a 4wd pickup.

judimasters | August 23, 2013

Do you have any info on wiring for this to my single jetski trailer?

Vicelike | August 23, 2013

I admire your courage!

I needed multiple assists to secure my license plate.

Torklift Central | October 1, 2013

We appreciate all of the feedback about the EcoHitch from Torklift Central. If you have any questions about the hitch, please refer all questions to for a quick and detailed response.

In honor of National Plug in Day 2013 Torklift Central is offering $25 off their hitches.

For more information you can visit
Shipping is free to the lower 48 states to help reduce cost.

Use promo code: Pluginday2013
Expires October 5th 2013 | October 1, 2013

The above EcoHitch offer got me off the fence. I've missed my hitch mounted bike rack.

Pungoteague_Dave | October 15, 2013

bumped for update

Alex K | October 15, 2013

I order an EcoHitch during Teslive ($100 off) and finally got it installed a few weeks ago. I had it installed when it was in for service. The service center took it over to their preferred body shop to have the nose cone painted body color and have the hitch installed. Hitch install was about $300. I would have done it myself, but all my car lifts are currently being used for non-car storage.

@Pungoteague_Dave in a previous thread you mentioned a 27% reduction in range transporting bikes. What bike carrier do you have and do you have any pictures of the bikes on the carrier?

I just got a new Küat Sherpa bike carrier, but haven't hooked it up, let alone transported any bikes. I was thinking of taking it up to my mountain home which is a 200 mile 4000ft elevation gain. Usually on a range charge I arrive with 35 miles remaining, but if I loose 27%, I would not make it. Luckily, there is an RV park at a casino half way up.

Pungoteague_Dave | October 15, 2013

Alex - you can see the hitch with one bike on it here:

The hitch is a Saris Thelma, 2" hitch version, and the bikes are Trek Madone 6.9.

Roamer@AZ USA | October 15, 2013

Dave, Did the tax credits and deductions allow you to keep your own money as long as you spent it the way uncle sugar wanted you to spend it.

Subsidies where they, the Federal Government, take someone else's money and give it to you are ethically pretty sad and wrong.

Credits and deductions that basically say that the kind and benevolent government has decided it is ok for you to keep your own money if you spend your own money on things they like. If you don't spend your own money on things they like they will take it and give it to someone else who will spend it on things they like thru subsidies.

I would feel no guilt being allowed by the government to actually keep some of my own money.

We have evolved into a weird place where the government thinks all your money is theirs and it's OK for you to keep a little when they allow it.

Roamer@AZ USA | October 15, 2013

Thanks for the well documented information on the hitch. Pretty much convinced me to tow things with my truck and use the Tesla as a car. Bike hitch and bike rack good for local short trip use but probably not great for a cross country trip.

Excellent post. Thank you.

dtesla | October 15, 2013

I have a bike rack on my Prius. I loose about 20% MPG when my Tandem is on the back. I have always assumed it's wind resistance. A bike going sideways has a lot of it. That is why I made sure my Tandem would fit inside my MS.

Brian H | October 15, 2013

Alex, dtesla;

I wonder if a roof rack with bikes facing forward would have less range impact.

Mathew98 | October 16, 2013

@Brian H - If you put a glider on top on the roof of the MS, you can have a an instant tethered flight akin to flying a kite. Let's worry about the landing part at some later date...

Anyone interested in parasailing on top of a moving MS?

jeff | January 25, 2016

Hey Dave--

This didn't seem clear to me in your original post, or in the followup, so I will just ask directly: Do you notice any impact to range with just the hitch itself, with nothing connected to it? From the pictures, it wasn't obviously how much impact it would have to the drag.

Pungoteague_Dave | August 31, 2016

We see no impact from the hitch alone. We have the same installation on our newer P85D and have towed more extensively, including a small boat to Florida and back. I do usually remove the hitch receiver and install the magnetized) cover plate when not using the hitch, mostly for aesthetics, as we have seen no difference in wh/mi. It may have a slight cost, but not enough to notice.

Tesla uses a newer version of the Torklift system on the Model X, and it is showing huge range penalties for larger loads, often 50%+ loss of range when towing close to the 5,000 pound limit (I've seen videos showing 800 wh/mi on flat ground). It works fine for towing around town, home to marina or boat ramp for example, but basically makes towing anything of significance nearly impossible for long distances (over 100 miles).

Watt fun | August 31, 2016

This is fascinating, and I will save this link. Thanks, Dave. I would think that you could get an answer to the question being begged via Germany, which tests and mandates limits for towing even if the manufacturer passes. For specific example, the Smart car, both the diesel (as in Canada up to 2009?) and the gasoline version have government safety tests which can be used. I saw a blacksmithing operation in New Brunswick use a diesel Smart with a mini trailer; 1.5 inch and Class 1 although MB always specifically excluded the Smart from any tow ratings officially in Canada. I believe it was 450 kg/990 pounds on the German government site for a 40 HP turbodiesel Smart!!

I was wondering--what is the approximate weight of the bike carrier AND bikes when attached?

I have a 13 foot Boler house trailer--fibreglass, very aerodynamic, and very very low centre of gravity, and only 760 pounds loaded. I have noticed that my mesh utility trailer at 500 pounds is much more of a drag/hinderance than the Boler, which is so smooth and stable on 13 inch car wheels/tires that I have often momentarily forgotten I have been towing a trailer on the highway until I look in the mirrors. Virtually unaffected by winds. In other words, perfect for an EV such as an S. I used to tow the Boler with everything from a Studebaker flathead 6 with 100 hp, to a decrepit 1993 Toyota Corolla automatic with 350,000 km and bad valves, up to larger and more capable ICE vehicles, and someone I know tows his Boler with an ancient Toyota Tercel 1500 CC.

Silver2K | August 31, 2016

is it easy to remove the bumper cover? also does it void the warrantee if service sees this on the car?

Pungoteague_Dave | August 31, 2016

@wattfun "I was wondering--what is the approximate weight of the bike carrier AND bikes when attached?"

Depends - I use two different racks for different type bikes. More important than the weight is the size and location. We see only about a 15% wh/mi cost for our carbon fiber Trek Madone road bikes that weigh 14 pounds each, so with two about 70 pounds including the rack.

However, we see a 25% range reduction when using our heavier rack for two Saris Disc Trucker touring bikes that weigh about 35 pounds each, so about 120 pounds total hanging off the back. I don't think the weight actually makes any difference - the issue is that the rack for the touring bikes puts the bikes about 10: further back from the car, and they are a big parachute back there, making MUCH more drag than when using the lighter, closer rack and the smaller carbon fiber road bikes.

@SilverP85plus "is it easy to remove the bumper cover? also does it void the warrantee if service sees this on the car?"

See my posts on the topic for more detail. It is an ordeal. Torklift provides good instructions, but I would not do it without having an auto lift. You must remove both wheels simultaneously, remove the interior of the car around the hatch opening, so unless quite handy, it is a job for an auto body place. You must cut a big hole in the cover, offset to one side. I did it perfectly on my first MS, but accidentally cut to the wrong side on the second one I installed, and had to buy new cover. The old saw - measure twice, cut once, was followed, but i still screwed it up despite having done it correctly two years prior.

Silver2K | August 31, 2016

thanks for install info! you're right I wouldn't even attempt it.

does it affect warrantee when spotted by service? did it at least affect yours?

Pungoteague_Dave | September 1, 2016

A hitch on the MS apparently does not affect warranties, although Tesla says there is no towing rating for the MS. We know this for two reasons. First, Tesla's shop in Rockville installed one for a customer in the early days. They no longer do this, referring customers to a preferred body shop. Second, they have featured Torklift at Tesla events. In any case like this, warranty law is also a protection. Warranty coverage may only be denied by a manufacturer if they can demonstrate that the aftermarket modification was the cause of whatever issue is subject to warranty claim. In my case, the only thing that came close was two drive unit replacements on our first car with the Eco-hitch. However, denying the repair on the basis of towing light trailers or carrying bicycles would have been absurd.