ICE on/off... on/off
 

I am a recent owner of a new 2009 TCH. Call me old fashion, but I was always taught that the majority of wear and tear on a motor is starting the car.

So, is this no longer true?

Re: ICE on/off... on/off
 

The ICE is not a standard setup. It doesn't use a starter for one to restart your engine. The electric motor brings the engine up to over 1000 RPM before engaging the fuel and spark plugs to reduce starter wear and gas consumption. Also, Toyota recommends 0w30 synthetic which has an extremly low (cold) startup viscosity (0) while at the same time has normal viscosity at running temps (30). This reduces the effort needed to start the engine. That is just two things engineered differently. I'm sure some engineer geek could tell you quite a few other differences.

Re: ICE on/off... on/off
 

wiredup,

ruc is correct in the start procedure. The ECU spins up the ICE to roughly 1000 rpm, makes sure the oil presure is up and then allows fuel and spark to the engine. Startup friction is gone using this method.

Re: ICE on/off... on/off
 

Still VERY true, but must be put in proper context.

Starting an engine that has fully cooled overnight, CHILLED in winter, is still pretty hard on any car engine. Not as bad as it used to be back when RAW gas, virtually, was used to start those big V8's, but still pretty rough.

But with the hybrid most starts, restarts, are with the ICE fully warmed to normal operating temperature.

And the other comments are correct, you have a 3 phase synchronous AC motor permanently attached, SOLID COUPLED to the ICE's output drive shaft. No traditional starting motor to mechanically dis/engage the flywheel. The ECU knows EXACTLY where the rotor of that motor is at all times so just a small partial rotation of the stator field, as little as 90 degrees, of that AC motor and the ICE is "fired".

Re: ICE on/off... on/off
 

Thanks--this really helps and makes sense.

Re: ICE on/off... on/off
 

I suspect that some of the noises that we hear when we walk up to the car is an electric oil pump that gets oil up into the valve area and elsewhere. This will also mitigate the more frequent ICE on ICE off cycles.

Re: ICE on/off... on/off
 

In conventional cars, the big items at engine start time are the starter gear being meshed (rammed) into the flywheel start ring, and the very high current draw required to turn the engine with only 12 volts (and often less) available. Once it starts, some more mechanical stress when the starter solenoid is cut off and the start gear disengages from the running engine.

Also, once the engine fires, it is on its own and required to instantly supply at least 100% of the power required to sustain idle.

None of the above is true for a hybrid.

Re: ICE on/off... on/off
 

I had read (somewhere) that the - on a stopped engine - HSD / Starting system used a crankshaft position sensor to sense exactly what cylinder is at or slightly after TDC on it's compression stroke, then a prime spray of fuel hits that cylinder along with a spark. Obviously with little or no compression in the cylinder, what motive force there would be would potentially be very slight - but perhaps enough to get the next cylinder in the firing order to compress it's mixture and fire etc..

I would love to read more on this topic if available anywhere...

Re: ICE on/off... on/off
 

Almost ever time I start the ice after the TCH has sat over night. I noticed I can go forward or backward (no throttle, just rolling) and it will roll for 4 or 5 seconds then the ice will start.

Here again the oil is getting up into the engine and valve train. Once the ice is up to operating temperature, the engine starting and stopping does not hurt it.