Towing a Prius

I don't know, but I do know that the manual with our 2014 Prius says that the engine always runs at speeds over 42 mph, just as our previous Prius's did.

Ed

While I have no plans of buying a 3rd Gen Prius (2010 or newer) it has a much higher speed (60+ mph electric only) before the gas engine has to turn to prevent damage to MG1. This would make towing one better as the engine could stay off, maybe all of the time. I have not been able to find a definitive max speed before the engine has to spin (not run). The 3rd Gen has a second normal planetary gear that decrease the ration between MG1 and MG2 from 2.6 to 1.05. This alone should more than double the previous 43 mph use of the engine plus the newer electric motors are rated double the rpms (13,000).:h ??????? Anyone, anyone.

When I drive my Prius at speeds over 42 mph, the engine runs all the time as we all know. If I watch the display on the dashboard, every now and then, the battery discharges. I believe this is why we can't tow the Prius without the ignition on. What is happening when driving is that the battery needs to discharge occasionally so it doesn't overcharge. In order for this to happen, I am guessing the ignition has to be on, and probably the engine also.

Ed Headington

cpoo wrote:
False, not full. Gas has to activate to balance the speed of the planetary gear .

With electronic injectors the engine can turn without any fuel being applied... coasting down a hill the engine is spinning, but not running.
The smaller of the two three phase motors is the one that spins the engine and charges the battery. Not sure if it can do both things at the same time... kind of think it can. So, if it can then it will be full of fuel and if not then it will be down a little.
OK, how's going to try this and report back.

*I did go and check on this: If you put it in the Neutral position (there is not a actual neutral and the engine does not drive the wheels directly) , it does not charge the battery so the engine would have to start up to charge the battery which is spinning the engine over 42 mph. If you tow it in the drive position I think you'll still have a full tank at the end of the day.

Ivylog wrote:
I would say True, 'BUT not only are you going to put miles on the odometer, at any speed above 42 the engine has to turn over and the compression release would be activated (see my video link). Pulling it behind a MH would be the same as coasting down a hill.
At the end of the day would the fuel tank still be full?
True

False

Why?

cpoo wrote:
False, not full. Gas has to activate to balance the speed of the planetary gear .

So my guess is that it would be say not quite but close to full probably would get close to the 128 MPG's I got in my MDX when I left it running once - no on second thought more like 250.

I really have no problem letting the odometer run - would really like to know the actual milage.

JMHO,
Busskipper

False, not full. Gas has to activate to balance the speed of the planetary gear .

I would say True, 'BUT not only are you going to put miles on the odometer, at any speed above 42 the engine has to turn over and the compression release would be activated (see my video link). Pulling it behind a MH would be the same as coasting down a hill.
At the end of the day would the fuel tank still be full?
True

False

Why?

Sorry to come in here late with this question but - if I had a base plate for a/my Prius/Constant Velocity Transmission and left the "motor running" - I could tow it? Miles would show on the odometer but it would not damage the Transmission.

True?
False?

Why?

Busskipper

While I have not put mine on a dolly yet, I see no reason to leave the key on... sorry no key to turn so pushing the start button without putting on the brake.

After you get the Prius on the dolly and locked down, you don't need to leave any of the power on. Just make sure you don't have the E-brake set.

The Prius manual show it's OK to tow with the front wheels on a wheel lift. It also says you can pull it short distance and at slow speeds with all four on the ground BUT someone has to steer and brake it. I would say in this case you need to hold the brake while pushing the start key so you unlock the parking brake before pulling it.
At speeds above 42 MPH the engine has to turn, even if it's not running. See video link in my post above.