Pre-start the ICE?

Not to be overly critical, but if you need the ICE to safely make a left turn, you shouldn't make that turn. The Prius has plenty of low end torque with only MG2.

Tom

 

As the Prius does not have any kind of torque converter, all the power at low speed comes from MG2 (can't run an ICE at 0 RPM...). Having the ICE run from a stop wouldn't serve any purpose, except feeding a bit more power to MG2 by generating current from MG1. I think you misinterpret the fact that the car makes no noise at all while accelerating from 0 MPH as having no power. Floor it if you want and look at the speedometer instead: you are indeed accelerating briskly.

 

MG2 is Motor-Generator 2, which is the big electric motor powering the drive wheels. MG1 is the small motor-generator attached to the sun gear of the PSD. MG1 is used to start the engine (ICE) and to provide virtual gearing through an electrical path: ICE to MG1 to MG2 to the wheels.

The ICE kicks in during the turn because it makes sense for the ICE to run in a high demand situation. It is inefficient to pull charge from the battery only to put it back again.

Getting back to your original question, at low speed MG2 is capable of delivering all the torque the tires can take. Adding more power won't make the car accelerate any faster. If you need more performance you should consider a different car, preferably something with wide tires and a big engine.

I find my Gen II Prius pulls away from other cars when I leave a traffic light. It's not that I can out muscle the fast cars, but the Prius has a lot of low end torque. Don't be afraid to press the gas when you need it.

Tom

 

It is possible that the ICE comes on during the turn, to power MG2, as MG2 can draw 50 kW when used to the max. (The battery provides about 20kW and MG1 can provide about 30 kW when the ICE is on)

I am not sure how slow the car can be going to have the ICE power the wheels, as opposed to powering the Motors. The Simulation I use hints the ICE could go 2700 RPMs at 0 MPH.
A simulation of Prius's Planetary Gear

 

The defroster does not bring on the ICE. On the left turn issue, are you using the Power mode?

 

couldn't tell you if ICE comes on in left turns but you could always put it in PWR mode before making the left.

 

I think you just need to spend more time behind the wheel of your new Prius. The car is in no way dangerous when making a left turn. If it bothers you that ICE is not on immediately then floor it if you consider it a big deal. I have never had any problems with left turns at all. Now try to perform a quick right turn while traffic is moving fast then have traction control kick in and you got yourself a problem. Damn 2005s.

 

You can also try standing on the brake and pressing the gas pedal right before you expect to take off. This will turn the ICE on but you won't move. It works on the Gen IIs anyway.

 

Cruise control does not keep the ICE on unless the speed setting exceeds 45 mph...

 

You -CAN- force the ICE on by turning on the A/C system with the temp setting calling for heat, -AND- the engine temp below 62C during warmup or below 50C after warmup. The temps may be slightly different on the GIII. I'm more familiar with the GII.

I -think- you can also force the ICE to run if you shift to another "gear" (can't remember which "gear" it was, maybe "P", but I was using it to force the engine to warmup faster while waiting at a long light). Once in the "other gear", press the accel. pedal (with the other foot on the brake). It may -still- delay you, however, as you still have to shift back to "D".

If the ICE is running as you approach the intersection, shift to "N" and the ICE won't shut down. Then when you get a break in traffic, shift to "D" and go.

-I- wouldn't do any of this (any more). I quit trying to force a faster warmup. It's all distracting you a bit from traffic. Not a good thing.

 

Eco or Power mode both produce the same amount of power. The only functional difference in this example is that you have to press harder on the gas to get the power. If you floor it in either mode you will get full power.

As for praying that the restart system never fails, this is no worse than any other car. What if your engine stalls in a normal car? You don't have an electric motor to pull you through the intersection.

Don't look for problems. Borrowing trouble is a fool's game.

Once again, there are two reasons that the ICE comes on: 1) To keep from discharging the HV battery, and 2) Provide more power if needed. The control logic in the Prius does the thinking for you. It's not always perfect, but it does a good job. When you step hard on the gas, it says to itself: "Well, it looks like we must be going someplace. I better start the ICE." If you creep away it says: "Hmmm...It looks like we might be in stop and go traffic. I think I'll wait a minute and see if we need the ICE."

The control system can't look ahead and see what's coming. In that respect you as the driver could help if there was some way to tell it that you are going to need a lot of power. Toyota elected to keep everything automatic, as manual controls are often misunderstood and misused by average drivers.

MG2 and the battery were sized to give good acceleration without the ICE, which is why it is fine that the car waits to kick on the ICE. This is one the main reasons that automatic control can work in the Prius.

Tom

 

Note that the -main- reason the ICE starts when it does is to limit current from the traction battery. It can be damaged if they let the current get too high and it would also overheat. So the ICE runs letting MG1 provide extra current to MG2 and also to provide torque to the wheels. Of course it would start a little later anyway to maintain charge state in the battery.

So the OP is correct, in that you -DON'T- get full torque to the wheels unless the ICE is running. It's limited by the current limit the system has set when the ICE isn't running. Which is why you often see two numbers for power and torque to the wheels. This confuses a lot of people.

 

There is a way. Step on the brake hard, and at the same time press down the gas - this will start the ICE. This trick is used by some people to charge the traction battery but you can use it to make a left turn. I have never felt the need to do this as the Prius has good initial pickup.

Rumple

 

Shift the transmission from "D" to "B" while waiting to complete your left turn, and if the engine is running it will not turn off.

If the engine is not running when you shift into "B" then rapidly press and release the gas pedal to start it.

For best mileage, be sure to shift back into "D" after you've completed your left turn.

 

Maybe you should give Power Mode a try...

I have used it a couple of times from a "cold start" when there is another vehicle beside me and the driver thinks he's going cross over in front of me. By the time I overcome the G-force and pull my head off the head rest, the other car is in my rear view mirror.