Flatbed Towing

[EPower]

Just wanted to share my recent experience.
I am aware that the MIEV is not designed to be towed in the conventional way and we should only have it "Flatbedded". My question is: "Would a tow company be liable for damage?"
I would assume that not all towing companies are aware of this and probably would claim no liability for damage for towing with the wheels on the ground.
In my case, a tow truck was ready to "hook-up" when I arrived two minutes before "rush hour, no parking" time was about to go into effect. I was lucky.
My suggestion is that Mitsu produce a decal for the front and rear windows and mail them to us or provide them at next service appointment.
In any event, I will at least tape a note in my windows in hopes that it will be observed.

 

[acensor]

Just wanted to share my recent experience.
I am aware that the MIEV is not designed to be towed in the conventional way and we should only have it "Flatbedded". .

This mandate (don't tow with wheels on the ground, which I THINK I later saw as "don't tow with BACK wheels on the ground) is a bit puzzling and raises a possibly serious question:

How is towing with wheels on the ground DIFFERENT from putting the car in neutral and coasting down a long hill (which some, or at least one, of the experienced members here recommended as a range stretching technique)?
In both cases the wheels are being passively turn by an outside force on the car (gravity in one case... a two cable in the other?

Does that mean if we coast down a hill in neutral we can damage our cars?

Alex

 

[JoeS]

EPower, I'm confused: if you're not around, how would the towing company get the vehicle out of "P" in order to disconnect the drivetrain-locking pawl? I assumed they'd either stick the rear wheels up on a dolly or simply drag the vehicle up onto a flatbed truck, rear tires not turning.

acensor, a year ago we had some discussions on coasting in Neutral:
Neutral and Hypermiling
ASC and Neutral

Even though I do indeed coast my iMiEV all the time in N, suffice it to remind everyone that the owner's manual specifically says not to do it and also warns against towing the iMiEV (pity, as it would make an ideal RV 'dingly').

I don't recall the details of a discussion as to the reasons why towing the de-energized iMiEV in N would be damaging.

 

[PV1]

This may be because while we are coasting in N, the controller is powered up. Towing in neutral, the controller is off. I think they say don't do it because an unpowered controller will be energized by the rotating motor, causing an overvoltage somewhere in the controller. When it's powered up, it can recognize that the motor is turning and safeguard against the voltage. My theory.

I'm thinking the car will act the same as my wind turbine. It has a 3-phase AC generator hooked to a controller to output 12 volts DC. If the turbine has power feeding it, it will run properly when the turbine starts spinning. If there is no power feeding it and it starts turning, it will build up voltage and pulse the electronic brakes rapidly, wearing out the turbine.

 

[EPower]

For JoeS

I have no idea how he was planning to hook-up but he said he was waiting for the bewitching hour and if that was my car I should move it now. Also, it was a "one way" street and he was parked in front of the MIEV. It just set of alarms in my head and I was wondering if I had dodged a bullet, like what kind of damage and what cost to repair and what can I do to avoid that concern in the future.

 

[Don]

I really doubt that any experienced tow truck driver would attempt to tow any car with the driven wheels on the ground . . . . plus, as Joe pointed out, just like any other car, when the transmission is in Park, the wheels aren't going to turn anyway . . . . and he would definitely know that

When you tow any car in neutral with the driven wheels on the ground, the gears are all running on the backside of their teeth, which is permissible of course for short periods when you are in reverse or decelerating down a hill, but to do that at freeway speeds for mile after mile will give you a noisy gearbox in short order . . . . if it doesn't break something first. This is why 4WD vehicles use freewheeling hubs to disconnect the front axle from the wheels when used in 2WD operation . . . . it prevents the ring and pinion gears from wearing their backsides

The car *would* make an excellent RV 'dingy' if one could get a set of hubs mounted on the rear axles (like those used on the front axle of 4WD vehicles) so you could disconnect the drive train from the rear wheels - Pretty sure that could be done, but it would probably require machining some parts

Don

 

[acensor]

......When you tow any car in neutral with the driven wheels on the ground, the gears are all running on the backside of their teeth, which is permissible of course for short periods when you are in reverse or decelerating down a hill, but to do that at freeway speeds for mile after mile will give you a noisy gearbox in short order . . . .
Don

Hi Don,

Well, then the "to do that at freeway speeds for mile after mile will give you a noisy gearbox in short order . . ." still might have me concerned about the otherwise reasonable-sounding suggestion made in this group about coasting or even using engine braking (in our case regeneration) on a long downhill. Coming into southern Oregon across the Siskiyou pass on the I-5 has about 14 miles of downhill where most(?) vehicles are effectively decellerating routinely.
Surely(?) you can't believe all those cars with standard trannies are wiping out their gearboxes on that 14 mile run (longer than many wheels on the ground tows would be)?

An of course remember in our i-cars we have no transmission gearbox,
so that alone can't be the reason Mitsubishi says "never tow it?"

Just pondering out loud. :?

Alex

 

[Don]

No, I don't believe only 14 miles would do anything . . . . probably not even 140 miles or 1400 miles - But if Mitsu did say it was OK to tow the car with all 4 wheels on the ground, the some joker would try towing it from San Francisco to New York and then try and cash in on his warranty when the gearbox fell out of the car around Kansas City - So, they cover all cases by just saying 'NEVER tow it'

Most small car manufacturers (including Mitsu) also say to never tow a trailer and that's just so they can legally be protected from any and all 'unusual' occurrences when someone does tow something . . . . they warned you not to

. . . . and we do have a 'gearbox' . . . . some would even call it a transmission, though it's just a one speed transmission - It couples the motor to the axle with about a 7:1 gear reduction. We have no ring and pinion gear like most RWD cars do. Most transmissions don't really mind running on the backsides of their gear teeth like ring and pinion gear-sets do. Maybe our trannies wouldn't fall apart near Kansas City . . . . but Mitsu is covered if one did

Don

 

[EPower]

So if I understand it correctly from all this discussion...

If I'm with the MIEV, needing a tow, I place gearshift into "N", handbrake off, key in "ready" position and if rope tow all four wheels on the ground or if truck tow rear wheels on ground is ok.

Now if picked-up by tow truck and MIEV is locked, handbrake on and I'm not around, hopefully it should be placed on a dolly to be safely towed.

I think I understand what you are saying about Mitsu covering themselves by saying what they say about towing and being towed but I just wanted to know how to respond to the events.

I appreciate your enlightening comments.

 

[NeilBlanchard]

This may be a moot point for some tow trucks - the wheel track on the i MiEV is too narrow for some types of tow cradles. The type that have hydraulic arms that capture the wheels on the inside may be too wide, and they would damage the tires and/or the wheels and/or the suspension.

I tend to think that towing with the rear wheels on the ground could be done without a problem, since coasting in neutral is fine. I'm fairly sure that "neutral" is an electrical mode, and it may not even be possible to put it in neutral without the car being powered up? Coasting in neutral doesn't create any regen, so it can't power anything, it seems to me.

I'm guessing that the manual is in CYA mode?

 

[acensor]

....I tend to think that towing with the rear wheels on the ground could be done without a problem, since coasting in neutral is fine. I'm fairly sure that "neutral" is an electrical mode, and it may not even be possible to put it in neutral without the car being powered up? Coasting in neutral doesn't create any regen, so it can't power anything, it seems to me.

I'm guessing that the manual is in CYA mode?

Maybe I'm missing something, but seems to me that short of a flatbed being able to get the MiEV up into it, the preferred way to tow would be to lift the back wheels off the ground and tow with front wheels on the ground.

Anyone differ on that?

Alex

 

[NeilBlanchard]

You'd have to lock the steering wheel with the wheels straight. And the cradle carrying the rear wheels have to fit the narrower than typical track, and not damage anything.