Using the i3 to Tow

[Mastedon]

We are looking to install the TorkLift hitch on our 2015 i3 and want to know if anyone else has installed a hitch, what brand, any problems, and what kind of harness did you use.

As the dealer mentioned, the i3 is not designed for towing and we get that. We like to go biking and want to use our bike rack on this vehicle. I've typically just bought a trailer lighting harness and installed it into existing wiring on our other cars. But I want to find out if the BMW harnesses for other models are specially designed to "plug-and-play" and would work on this vehicle. I don't want to install the TorkLift harness which is apparently a voltage sensor type system which does not require splicing into exiting wires.

Any other tips would be appreciated.

 

[Obioban]

I have the etrailer hitch with a bike rack. Works well, no issues.

I also am fine with towing a small trailer short distances if useful. Hitch is rated for 2000 lbs of towing-- perfect for moving a lawn mower, etc.

 

[bwilson4web]

Has anyone seen a trailer wiring kit?

I have the receiver and a small, Harbor Freight trailer. But I really need running, stop, and turn signal lighting.

Bob Wilson

 

[Anonymous]

Has anyone seen a trailer wiring kit?

Torklift has a kit that is supposed to work with the i3 I know that a year or so ago an i3 owner posted details of his trailer hitch installation (Facebook group, I think), complete with working light wiring, but that part of the install was not in much detail.

https://torkliftcentral.com/rving-and-towing/electrical-wiring/t-one-connectors/wiring-harness-tesla-roadster-and-model-s-119251

 

[bwilson4web]

Excellent! I'll contact them on Monday. But my need is immediate.

So let's see if these images come through:
https://www.icloud.com/iclouddrive/0WC-O717qEzwUCLsAvW9g9llw#trailer_wires_010

https://www.icloud.com/iclouddrive/03uoqiOltv6Twj5OsrfheNM3g#trailer_wires_020

https://www.icloud.com/iclouddrive/0-6EcPjTYnW2McNm7krIrSpiQ#trailer_wires_030jpeg

A quick kludge, power come from the 12V aux port and feeds the 4-wire trailer cable. The toggle switch allows manual enabling of turn signal lights. The running lights are always on. The stop light requires a pair of diodes but our load is low enough the I3 lights should work.

I'll check my junk box and perhaps put together a simple, next generation box for a permanent installation. It is always nice to have trailer with the dimensions of a pickup truck bed.

Bob Wilson

 

[alohart]

It is always nice to have trailer with the dimensions of a pickup truck bed.

I would be concerned by the lack of strong attachment points on an i3. Unfortunately, the i3's aluminum frame apparently doesn't extend far enough to the rear of the car to provide strong attachment points.

I believe a tow kit is available for your Model 3 (maybe only in Europe). If so, that would almost certainly be a better tow vehicle.

 

[JASmith]

I have the etrailer hitch with a bike rack. Works well, no issues.

I also am fine with towing a small trailer short distances if useful. Hitch is rated for 2000 lbs of towing-- perfect for moving a lawn mower, etc.

I know almost nothing about EVs, but am not new to towing. The limiting factor on your hitch is going to be your tongue weight, and it probably can't handle more than 200lbs, unless that's what you meant to say.

The shorter the wheelbase and more rear biased the weight of the vehicle, the more tongue weight you need to be stable at speed so you'd want close to 15%. The i3 also has really skinny tires though, and I'd be surprised if you also don't end up overloading them if you tried anything close to 2K lbs. Lastly there's a matter of heat dissipation which can be a big issue, and that could overtax the vehicle.

I'd just rent a uhaul truck when needed, they aren't expensive, and it'd only be expensive if you're towing often at which point I'd trade in the i3 for a little Passport or something like that.

IMO its silly to mount a giant hunk of metal on the back of the vehicle anyway when BMW went to such extreme lengths to shave every pound possible, even putting in less speakers than expected, even if just carrying bicycles. I'd get yourself one of the temporary bike rack mounts that go on the back so you can remove it when not needed.

 

[eXodus]

I have the etrailer hitch with a bike rack. Works well, no issues.

I also am fine with towing a small trailer short distances if useful. Hitch is rated for 2000 lbs of towing-- perfect for moving a lawn mower, etc.

I know almost nothing about EVs, but am not new to towing. The limiting factor on your hitch is going to be your tongue weight, and it probably can't handle more than 200lbs, unless that's what you meant to say.

American Trailers with their crazy tongue weights....

My German Horse Trailer - 4000lbs has a tongue weight of 100lbs. (50kg) (any random VW Golf-sized car can tow that one)

My US Horse Trailer - 5000lbs has a tongue weight of 800lbs (you need a Fullsize Pickup to tow that)


Both trailers tow fine. Just the US setup needs like 3x as much fuel.

 

[JASmith]

American Trailers with their crazy tongue weights....

My German Horse Trailer - 4000lbs has a tongue weight of 100lbs. (50kg) (any random VW Golf-sized car can tow that one)

My US Horse Trailer - 5000lbs has a tongue weight of 800lbs (you need a Fullsize Pickup to tow that)

Both trailers tow fine. Just the US setup needs like 3x as much fuel.

European tow standards are basically unsafe, and you regularly see tiny vehicles towing much too large of trailers there with brake or transmission failures up hills or loss of control at speed, its pretty silly. Saw a Fiat 500 once towing a camper! If you're going 20mph on a level grade, fine, but there is a reason that tow ratings are so much different in the US as ours are, you know, actually safe for yourself and other drivers on highways and hills.

Not that more is better, but this demonstrates why US standards may lower fuel economy and put more load on the vehicle but are inherently more stable, especially important on a vehicle that has a short wheelbase and is already tail heavy compared to most:
https://www.youtube.com/watch?v=6mW_gzdh6to

 

[Pahaska]

Some years ago, I was using my Chevy Blazer to tow a stock trailer occupied by a 1500# bull. The shotgun trailer had a moveable gate at the fore and aft center. I put the bull in the front section and secured the gate with a piece of fence wire since the latch was broken.

At about 50 miles per hour, the gate came open and the bull decided to move to the rear of the trailer. I used both lanes and both shoulders before I got the Blazer under control. Thankfully, no one was coming toward me and I still had a fighter pilot's reactions in those days.

That is what a lack of tongue weight will do. I would not want just 40# on the hitch in anything bigger than a luggage trailer.

I don't think the I3 should be used for anything bigger than a bike rack.

 

[eXodus]

European tow standards are basically unsafe, and you regularly see tiny vehicles towing much too large of trailers there with brake or transmission failures up hills or loss of control at speed, its pretty silly. Saw a Fiat 500 once towing a camper! If you're going 20mph on a level grade, fine, but there is a reason that tow ratings are so much different in the US as ours are, you know, actually safe for yourself and other drivers on highways and hills.

Not that more is better, but this demonstrates why US standards may lower fuel economy and put more load on the vehicle but are inherently more stable, especially important on a vehicle that has a short wheelbase and is already tail heavy compared to most:
https://www.youtube.com/watch?v=6mW_gzdh6to

Nothing in that video let me assume that European standards are unsafe. You need more weight in the front of the trailer then in the back. I fully agree with that.

There are various factors which impact tongue weight - including the distance to between the trailer axle and the hitch. If you lengthen that distance - you lower the tongue weight. While still keeping the trailer front heavy for stability.

Euro trailers are equipped with substantial break systems. Most trailers have hydraulic brakes, so the strain on the tow vehicle is not as big as you think. The electric brakes in my US trailer are weak in comparison. The Euro trailer brake system can stop the car + trailer by itself - easy.

 

[JASmith]

Nothing in that video let me assume that European standards are unsafe. You need more weight in the front of the trailer then in the back. I fully agree with that.

There are various factors which impact tongue weight - including the distance to between the trailer axle and the hitch. If you lengthen that distance - you lower the tongue weight. While still keeping the trailer front heavy for stability.

The video was demonstrating why the much lighter tongue weights allowed in Europe are less safe at speed.

The full standard in the US is called J2807, and basically its just a far more stringent test than in Europe. For example, this test requires a certain level of acceleration and braking performance up and down 12% grades, it has to pass a handling test for obstacle avoidance while towing testing trailer sway and understeer, at high speeds and it has to do this with two passengers, a light gear load, and at least 10% tongue weight.

Neither the US nor Europe regulate the trailers themselves in axle to hitch distance for example, for obvious reasons that its not always practical or necessary, rendering that argument a bit moot.

European tow ratings are so huge because for the most part they do none of the above testing and tongue weights in many countries are allowed to be as low as 3%. Most get around this lack of safety testing by simply lowering trailer tow speeds to 50mph or slower (compared to Texas for example that has a max towing speed of 85mph), and having a legal system that tends to leave manufacturers alone when accidents occur.

https://www.youtube.com/watch?v=lAfZ1N56qjY
European logic: "Hmm, I think the problem here is he's running a bit rich".

 

[eXodus]

The video was demonstrating why the much lighter tongue weights allowed in Europe are less safe at speed.

The video demonstrate what weight distribution in a trailer does to stability. If you move both weight stacks more to the axle to of trailer - you still got the same weight - yet a longer tongue to center of gravity ration - and thus a more stable running trailer.

On double axle trailers in Europe you got another feature US trailers usually don't have - toe in alignment. Euro trailers are self centering.

The axles in a US trailer you can mount axle forward or backwards - doesn't matter - since the tires are parallel. Not so on a Euro spec trailer - they got a forward direction - with slight toe in. If you mount that thing the wrong way around - that trailer sways like heck.

Since most of Europe doesn't allow trailers to be run at more 100km/h it's also obvious that there is no emphasize to design that feature in.

So there are various ways to design a safe trailer - on of them is having a large tongue load. But there are many more.

 

[Obioban]

I have the etrailer hitch with a bike rack. Works well, no issues.

I also am fine with towing a small trailer short distances if useful. Hitch is rated for 2000 lbs of towing-- perfect for moving a lawn mower, etc.

I know almost nothing about EVs, but am not new to towing. The limiting factor on your hitch is going to be your tongue weight, and it probably can't handle more than 200lbs, unless that's what you meant to say.

The shorter the wheelbase and more rear biased the weight of the vehicle, the more tongue weight you need to be stable at speed so you'd want close to 15%. The i3 also has really skinny tires though, and I'd be surprised if you also don't end up overloading them if you tried anything close to 2K lbs. Lastly there's a matter of heat dissipation which can be a big issue, and that could overtax the vehicle.

I'd just rent a uhaul truck when needed, they aren't expensive, and it'd only be expensive if you're towing often at which point I'd trade in the i3 for a little Passport or something like that.

IMO its silly to mount a giant hunk of metal on the back of the vehicle anyway when BMW went to such extreme lengths to shave every pound possible, even putting in less speakers than expected, even if just carrying bicycles. I'd get yourself one of the temporary bike rack mounts that go on the back so you can remove it when not needed.

The REx engine (I don't have) weights ~300 lbs, so presumably I could have that much tongue weight before even being heavier than "stock" (including the tires).

The drivetrain limits power based on temperature. I hit that limit almost every time I'm on the highway, as it's can't sustain 94mph up hill over an extended distance. So, you can't overheat it.

I've actually towed my lawn mower since I made my original post. Couldn't actually notice it back there while driving :lol:

 

[eXodus]

The REx engine (I don't have) weights ~300 lbs, so presumably I could have that much tongue weight before even being heavier than "stock" (including the tires).

The drivetrain limits power based on temperature. I hit that limit almost every time I'm on the highway, as it's can't sustain 94mph up hill over an extended distance. So, you can't overheat it.

I've actually towed my lawn mower since I made my original post. Couldn't actually notice it back there while driving :lol:

I guess that the tongue weight is also relates to ripping the hitch from the frame. Not only capacity for the drivetrain.

More often then not - frames get bent and attachment points get overloaded - then the actually suspension/ engine being damaged. Suspension is are usually oversized by a considerable amount, to account for people not reading the manual and bad roads.

A friend accidental overloaded an old Volvo by about one ton. (just put in a few tiles in the trunk) suspension was fine - but the trunk floor caved in

 

[Obioban]

I guess that the tongue weight is also relates to ripping the hitch from the frame. Not only capacity for the drivetrain.

More often then not - frames get bent and attachment points get overloaded - then the actually suspension/ engine being damaged. Suspension is are usually oversized by a considerable amount, to account for people not reading the manual and bad roads.

A friend accidental overloaded an old Volvo by about one ton. (just put in a few tiles in the trunk) suspension was fine - but the trunk floor caved in

You're talking about overloading by a ton over spec, I'm talking about towing less than half a ton, within spec. Not sure of relevance.

 

[eXodus]

You're talking about overloading by a ton over spec, I'm talking about towing less than half a ton, within spec. Not sure of relevance.

that was out of context to the other post in the thread not related to the initial posting.

Just saying - that some weights are defined by suspension and some by frame. Half a ton 1000lbs is nothing - even for the i3 when you don't overdo the load on the hitch.

 

[wasosur]

I would be concerned by the lack of strong attachment points on an i3. Unfortunately, the i3's aluminum frame apparently doesn't extend far enough to the rear of the car to provide strong attachment points.