Does ECO mode hurt the engine in the long run?

IF......you have a conventional hybrid, versus a plug-in, it should NOT work that way.
My C kicks the engine on sitting in the driveway while I am finding sunglasses, adjusting the mirrors, etc. about 30 seconds after I "start" the vehicle. Regardless of climate control settings or outside temp.

 

Even when it starts the engine, that doesn't mean it has to immediately thrash the cold engine by shifting all the load to it.

Even when the engine starts in your driveway, you'll usually notice as you're driving off that the engine doesn't rise above idle much, and the car moves off mostly on electric. The car gradually adds load to the engine as the engine comes up to operating temperature. Sometimes if you mash the go pedal far enough, you'll override that and for that moment it will demand more power from the engine, then go back to babying it until it is warm.

So unless your driving conditions for some reason regularly force the cold engine to be thrashed, it isn't likely to happen often enough to fret about.

 

Fortunately, that isn't how warm-up actually works. The battery & motor provide a buffer so the engine doesn't have the burden of a full load, preventing strain.

 

4th gen Prius programming maybe allows more electric-only on start up?

 

please don't poke the bear

 

Let's try to clarify what others have said:
Just because the engine is RUNNING, does not necessarily mean that it is carrying a significant load......or maybe not any load at all if it is sitting still.

SO......the answer is: NOTHING that the engine is programmed to do on it's own will "hurt" it in the least.

With all of the really NASTY stuff that is going on all over the world these days, it is really kind of amazing that people have the time to worry about insignificant crap like this.

 

I get a little amused at just how many people fret about this. It's like the engineers who designed the most reliable car in the world were dummies.

As @ChapmanF and @john1701a pointed out already, the Prius really babies the engine when it starts up. To get an idea what's going on, make use of the split screen display on the speedometer and select the instantaneous MPG bar. Note that while the ICE is warming up, the car is getting close to or even over 100 MPG. That indicates that the electric part of the hybrid system is doing much or most of the work. I think this is mostly to minimize emissions since modern multi viscosity oils like the 0W16 in your car flow about like water in cold conditions. So, as far as wear and tear on the cold engine, I wouldn't worry anyway.

Also, the Prius routes the engine coolant through the catalytic converter so that the engine warms up incredibly quickly, again with the goal of reduced emissions.

 

... well, routes the coolant through an exhaust heat exchanger thingy, just abaft the (two) catalytic converter(s).

 

Right. I assumed a heat exchanger since just pumping it in there would be ... messy.

That's a GREAT picture, btw. Thanks.

 

they're probably frightened by the engineers yeoman duty on the gen3 engine

 

Only in the bad-old-days when you had to get a car idling smoothly - by balancing the choke and some judicious jabs at the accelerator did you have to idle before driving off.

Today - the recommendation by most manufacturers is to start the car, and drive off immediately - but don't load it excessively. In the case of a PRIUS, it won't over-rev as it's a fairly slow-revving engine, and some of the load is taken by MG2.

Idling on start will only risk glazing the bores.

 

It's not on all PRIUS - even in USA by the looks of it. We don't get it here.

 

Wow! Interesting.

 

But only if you live in Australia, where the pistons run upside down all the time.
Sorry but I think that is a ridiculous statement. Where did you pull that out from ?

 

In some threads, it's the bores who leave the rest of us kind of glazed.

 

Wow - 6 months! I think it took me like 3 days of Eco, before I got angry at it and went back to just keeping it in Normal.

 

Interesting thread. Did Prius always have Eco mode since Gen1? I have never driven Gen1 or Gen2, so I don't know for sure. But I know for sure it had Eco mode in Gen3. If driving in Eco mode all the time did cause bad things to the engine, I am sure we have heard of a class-action lawsuit by now. I for one, always drive on Eco mode. I don't think I have ever switched it to other modes except for the very first few times after buying my first PP.

 

The Gen 2 did not have ECO, PWR, etc. I can't be sure, but I'd be surprised if the Gen 1 did. It was introduced in the Gen 3.