Overheating Toad!

There are special considerations for towing a hybrid with 4 wheels down.
Some models even recommend against doing it at all.

If you have a hybrid, get the recommended procedure specific to your model.

THE MILEAGE SHOULD NOT ACCUMULATE AND THE COOLANT TEMP. SHOULD NOT COME ANYWHERE NEAR THE 230 F OR SO IT TAKES TO OVERFLOW. Something is definitely amiss.....and it could turn out to be expensive in the end.

I assume you have read and follow these guidelines:

Recreational Towing
Note: Put your climate control system in
recirculated air mode to prevent exhaust
fumes from entering the vehicle. See
Climate Control (page 107).
Follow these guidelines if you have a need
for recreational (RV) towing. An example
of recreational towing would be towing
your vehicle behind a motorhome. We
designed these guidelines to prevent
damage to your transmission.
You can tow your vehicle with all four
wheels on the ground or with the front
wheels off the ground by using a tow dolly.
If you are using a tow dolly follow the
instructions specified by the equipment
provider.
If you tow your vehicle with all four wheels
on the ground:
• Tow only in the forward direction.
• Release the parking brake.
Vehicles with Push Button Start
1. Start the vehicle by pressing the brake
pedal, and then pressing the ENGINE
START/STOP button until the vehicle
starts.
2. Press the brake pedal and shift the
transmission into position N.
3. Turn the vehicle off by pressing the
ENGINE START/STOP button once.
(Trip Summary appears in the left
instrument cluster screen when the
vehicle is off.)
Note: You can remove the key fob from the
vehicle while towing

Vehicles with Ignition Key
1. Start the vehicle by pressing the brake
pedal, and then turning the ignition key
until the vehicle starts.
2. Press the brake pedal and shift the
transmission into position N.
3. Turn the vehicle off by turning the
ignition key past the accessory position.
The key position is between the
accessory and off positions. See
Ignition Switch (page 127). (Trip
Summary appears in the left
instrument cluster screen when the
vehicle is off.)
Note: If your vehicle is equipped with an
ignition key, you cannot remove the key from
the ignition cylinder when the transmission
is in position N and the vehicle is off.
All Vehicles
• Do not exceed 70 mph (113 km/h).
• Place the transmission in position P,
start the vehicle, and allow the engine
to run for one minute at the beginning
of each day (you may need to press the
accelerator pedal in order to start the
engine). After allowing the vehicle to
run, place the transmission back into
position N and the ignition in the off
position.
Note: A SHIFT TO PARK or
TRANSMISSION NOT IN PARK message
may appear in the information display when
the transmission is in position N and the
ignition is in the off position.

I dont know anything about towing a vehicle beind an rv, but i belive i C-max is a hybrid. My understanding of a hybrid is that if you are not acelerating the wheels are generating energy to charge the batties? I would assume the car is in neutral with the key in the acc. Position or is there a way to put it in neutral and still get the key into off position?

How does the radiator look? Could you have picked up some substance (mud, tar, cottonwood duff, etc) that caused the overheat?

It sounds to me like the engine was turning over while being towed and the engine to heated up. Since you mentioned the additional 12 miles I'll assume your toad usually doesn't accumulate miles while being toad. It that's correct, then that's an additional clue that the engine was being turned over from being towed.

I don't think hot pavement would cause the problem or else people's cars would overheat from just being parked in a paved parking lot during the afternoon.

Bill