Will it hurt the ICE switching from EV to HV while doing 65mph?

No problem at all, it's deigned for the transition to work well. Remember you have HV battery at that time to assist and the car uses it.

 

Engine still has to go through a warm up cycle anyway, so, unless you really floor it, the hybrid defers to electrical energy from the battery until the cycle is complete. Exception: If you press the accelerator hard, then, it'll use both and the engine RPM will be high. But do not worry, you have 0W-20 synthetic oil, so, it shouldn't cause a problem.

Interestingly, on a very cold morning (a few ticks below the freezing point of water) last year, I was on an all electric journey and had to pass someone. Well the engine kicked on anyway, thus defeating the all-electric "EV Mode" drive setting, and the RPMs went to 3300 or so within one second. The engine did not squeal or make any abnormal sounds. Meanwhile, the coolant temperature was just below the freezing point of water... and eventually the warm-up cycle completed successfully. So, even in this cold scenario, a switch out of all electric to the hybrid system (HV equivalent) did not hurt the engine, so, your situation will be even less of a concern.

 

How do you know this is not hard on an ice cold engine?
Come on, you know it is not an ideal way to treat an engine.

These issues are just now being talked about in reviews of all the new 'lesser / not 100% EV' PHEV's.

 

Huh? Where did I say that this was ideal? I never said that and I never implied that. Nor was I aware that my engine was going to turn on, as I was expecting it to stay in all electric EV mode. I just...happened to discover that the car turned on its engine that morning. Who said anything about it not being hard on the engine?

 

Sorry.
Sorry for thinking you were defending this 'Type' of Not 100% EV - PHEV.
Sorry you didn't do the research before taking the PHEV plunge.

But I am glad that more people are taking this plunge just because it has Toyota and Prius on the back of the car.
It is a good thing in the Big Picture of the Clean Energy Future.

For me,, a PHEV was just a stepping stone to BEV ownership!

 

[Edit - clearing up some posts, ignore mine above as it was in response to another user, whose post is invisible now, and I can't edit mine because it's been a few hours, and I have no option to delete this one]

 

Invisible, deleted, whatever, I don't have mod access to see what went missing. If you want you can delete my posts, the ones that look out of place.

 

This is my thought as well, the PHEVs are designed to start the engine cold when cold at elevated speeds and is engineered to handle it (I.e. lean more on electric and less on gas, and this is proven by how quickly the HV charge drops when the switch over happens while heavy throttle). However, going full throttle forcing the engine on does seem to let the car stretch it’s limit a bit more to accommodate (with a bit of lag, at least from my experience with the PiP), but this can only be worse for the car overall, as pushing a cold engine cannot be beneficial whether it is giving it’s all or not. I am sure it was engineered that you are not going to cause any meaningful damage by doing this occasionally (for example, merging onto a freeway and noticing an 18-wheeler barrelling down on you at the last minute...), so a little planning ahead is usually best for the overall health of your engine.

For example, in my PiP, anytime I am leaving home with a full charge and I know I am going to travel more than the EV range (almost always), I run on EV to start, until I either get to the highway, or at least to a decent stretch of road where I know I will not be stopping for some time. While rolling, switch to HV to let the engine warm up while cruising, thus minimizing the “warm up penalty”. I also usually keep 3-5km of EV charge on tap for traffic jams or next start up, if I don’t expect to have a charge opportunity at my next stop, so I can once again get to a suitable cruising area to warm up. Just my $0.02.

 

The tolerances and lubricants used these days greatly reduce the importance of the extended engine warm-up periods which those of us over the age of 40 were lectured about in drivers' ed.

If you want to see how the electric motors in the Prius Prime trans-axle interact with the ICE, take a look at this lengthy and detailed video:

I think the video will confirm your appreciation for how well thought out the engineering is in the Prime's hybrid drive train. You'll also see how the electric motors handle the transition from being the primary motive power to handing off the task to the ICE.

 

I wouldn’t do it. Let the ice warm up at least 5 min before getting to freeway speeds. I merge onto freeways in excess of 60mph.

 

It would be interesting to see how many RPMs exist when it transitions at freeway speed. I drive in ECO all of the time and when it goes from EV to HV I have to depress the accelerator more to maintain my speed.

Posted via the PriusChat mobile app.

 

I have a ScanGauge which tells me the actually RPM in numeric value. If you were to get up to cruising speed (~60MPH) then switch on HV, the engine will warm up in normal range (approx 1400-1500 if memory serves me right), leaning more on electric until it gets up to temperature. It will rev higher if pushed though, and I think this is really the only time you may run the risk of added wear, but nothing serious (no more so than getting in an ICE car and putting it in Drive and flooring it. Not the smartest move, but won’t kill the car either). The Prius is smart enough to manage itself in such a way as to protect itself.

Just my $0.02, and I am no mechanic...

 

I drive that way every morning 5 days a week. I am in EV from my house until I am on the freeway and get my speed up to 65-75 MPH then switch to HV. It's also a slight uphill (mostly) for the next 14 miles or so.

When you swap to HV from a cold engine, the ICE hardly puts out any power while it is in warm-up mode (probably about 2-4 minutes, not sure). Almost all your power is coming from the battery pack in order to avoid putting stress on a cold engine. I also avoid any kind of hard acceleration until the engine has been warmed up for a few minutes. Sometimes it pisses people off behind you who want to be doing 85 MPH but what can you do?

Keep an eye on the energy diagram on the main display and you'll see that the engine icon will not turn "yellow" for a few minutes. You'll also see your battery charge start dropping quite quickly at 60+ MPH - don't worry, though, you'll get back to the same charge level when you first switched to HV. The Prime "remembers" what charge the battery was at when you activated HV mode and gradually recharges the battery to restore the charge used while the engine was warming up.

Keep in mind this is why you use 0-20W oil in the Prime! The "zero" part of that specification means that the cold oil is thin enough to be circulated through a cold engine quickly with the least engine wear possible. Upping your oil to 5W-20 or 5W-30 would be inadvisable to say the least IMO.

 

I just don’t think it’s wise to get onto a freeway where you know you’re doing a disservice to those around you because you are unwilling use the full capability of the anemic powertrain.

Also gives a continual bad name for Prius drivers.