DEFEATING ICE OPERATION

This observation could be evaluated if there was some way to measure the amount of gasoline saved by taking the load off the engine vs leaving it in a drive mode until it reaches 130°F and turns itself off. So it'd be interesting to follow up on this observation with some data. Not sure what metric to use, though.

 

Well obviously the goal is to not have the ICE run at all. But I believe the consensus was that when the engine runs at lower temps it produces more condensation but it eliminates this by the time it warms up properly (burns it off at higher temps). I am definitely no expert on this, just regurgitating what I've heard others say. But it seems to be fairly logical.

 

Again, just regurgitating here, not sure where I read it. I believe the engine does the same warmup cycle regardless whether you are moving or not. It simply uses the traction battery to move you during the warmup.

 

People were reporting clanking noises from the ICE the next time it started when it was shut down before it was completely warmed up. I believe there was even a Toyota TSB referenced. I will try to dig up the threads when I have a little time.

 

I've never heard a clanking noise when the ICE starts. Usually I can't even tell when it starts until a while later. Then I realize...yep 124 miles since the last time it ran. Or, oops, I accelerated hard to pass that car.

Mike

 

Here you go: Rough start after a few quick cold ICE on offs | PriusChat

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Seems a bit anedotal for me. But maybe there is something to it for people who just washed their cars, thus getting lots of moisture near it and/or people in colder climates. But even so...is it doing any damage? Or it is just adding a tad to normal wear and tear?

Mike

 

If you read farther down the thread, multiple owners were reporting engine knocking the next start after prematurely shutting down the ICE.

 

replacement intake manifold.

 

Lets see...

The warmup cycle costs about 10 cents in gas.

This is a wild ballpark, but say the worst happened and you had to get a new ICE out of warranty...what would that cost...maybe $5,000?

So in other words....if you think there is less than a .002% chance that shutting off the ICE prematurely is 100% bad for the car...than by all means, make that bet.

As for me, I'll just spend the dime.

 

I, myself, as well as lots of other people on this forum have gone the 124 miles in between times the ICE must come on. Not bragging, just letting you know since that's what you wanted me to do.

 

The warmup cycle stops when the Cat temp reaches certain (i recall 400 F) degree -- normal operating temp. The purpose is to prepare for hard acceleration with ICE.

I don't think it hurts the ICE if I shut it off before Cat temp is reached. I also don't pull over and reboot the car. If I arrive in my garage and PiP is warming up, I turn it off instead of waiting.

 

Are you more than 99.998% sure it does no harm?

 

I am not sure. It was my conjecture based on a SAE paper Toyota published on PiP. If it is harmful, I think Toyota would have some measure to prevent it.