Mainly EV mode but a little ICE use?

not necessarily on your commute, but a spitited hv drive once a week wouldn't hurt. but when the ice does start on your commute, make sure to let it finish the warm up cycle before shutting down.

do you never travel more than ev range? might be the wrong vehicle choice.

 

I understand your concern. I personally wait until the ICE shuts down on It’s own or 5 minutes. Unlike you this happens to me very infrequently.
How’s that for a non-answer?
Enjoy your Prime.
J

 

the engine will shut down on its own. if i get the feeling i'm not going to make it in ev, i hit the hv button a few miles before my destination to get the warm up over with, and back in ev mode as i pull in.
experience will help you with the decision process.

 

Yeah, during summer I have the same problem. I always run out of EV range just a few miles shy of getting home. Almost always, I pull into my driveway with engine still warming up. I changed my driving habit since then exactly for the same concern as you have. I now intentionally mix HV/EV on my commute to make sure engine warm up is complete well before I stop my car. In my local, this is fine for gas cost less than electric.

 

How about running that last mile or two in “charge mode” that way it feels like your getting more for that ICE time.

 

This used to happen pretty often with my PiP which is one of the main reasons I got the Prime. Happens very rarely now. I'm in the camp of those who favor running it at least long enough for it to shut itself off. I sometimes wonder if, at that point, it's really warmed up enough, but it puts itself in EV, so I'd have to accelerate hard to get the ICE to restart. So, maybe good enough in spite of my misgivings.

 

at least you don't have to wonder what's happening inside the egr circuit...

 

As far as I know.

 

Well, how long do you want the engine too last? If you make no changes, I think the car will still easily reach 10 years or 150k miles without any major issue. Considering the little use the engine sees, you could probably transplant it into another car, and still get another 'lifetime' of service out of it.

If there is a any reduction to the engine's life in the car from this drive cycle, letting it complete the warm up cycle isn't going to help. It will actually mean more wear. The warm up cycle the Prius goes through is to get the best efficiency and lowest emissions. That actually doesn't take long. What takes more time is heating the oil up to where it provides the best protection and boils off the water that has gotten into it. Unless you are driving the engine hard, that takes longer than 10 minutes. 10 miles is what I remember hearing for the oil to reach operating temperature.

Shutting off the car before the catalytic converter is fully warmed up isn't going to harm anything. Letting the engine run long enough to finish warm up means letting the engine wear for a few minutes more than you need to.

Now, water build up in the oil could be an issue, if you go with longer oil change intervals that what Toyota calls for. The 10k mile or one year they call for is conservative of a PHEV. Assuming you are getting a charge at work. The drive home in hybrid mode will take care of any water.

Charge mode runs the engine harder, so will warm up the oil faster.

With the redesign for the gen4, carbon build up there shouldn't be an issue.

 

but that's the question, isn't it? shouldn't, wouldn't, couldn't? we really have no idea of the consequenses of short cycling the engine, for better or for worse.

 

Short trips were hard on cars. Still are to a degree, but better design and manufacturing of the components and better oil have reduced the wear and tear engine start up causes. Look at automatic transmissions. Couple decades ago, those needing work at some point was expected. Now the speciality transmission shops are gone if they didn't expand to general car work. Then hybrids go a step further by spinning the engine up to a higher speed, and getting oil up to pressure, before firing it off.

The main point of the warm up period is for reducing emissions. The first step is getting the oxygen sensors warmed up so the ECU can put the engine in closed loop, which happens quickly according to the Scanguage. Then it is waiting for the cat to warm up. Neither of those things are part of the engine. Getting the engine warmed up helps with efficiency, and thus some emissions, but if the warm up cycle was about protecting the engine, it would run it longer, or harder, until the oil was fully warmed up.

 

I‘ve never used it myself, but EV auto mode might be good for your commute. I gather the concept is to drive mostly EV, but use the ICE to augment the motors in high-demand situations, thus increasing range.

 

I experimented with EV Auto when I first got the car. The ICE never came on, even when I floored it. From what I've read here since, I get the impression that the engine has to already be warm. Or maybe it's that the SOC has to be below a certain point? Maybe someone here with more experience and who has hills available can write with more info.

 

OK, interesting...

I do occasionally run into cases where I know the battery won’t quiiiiite get me there. I always take the opposite approach to ICE usage in those cases:

Again, as best I understand it at least, the goal of EV Auto is to augment the motors when high torque is needed, most obviously accelerating from low speed.

To me, that’s the worst possible time to kick in the ICE! I instead kick the ICE in when it can run at high MPG — a comparatively-high- and comparatively-constant-speed part of the drive. If the %£@& computer insists upon burning gas to warm up the engine, then I definitely want it to move a fair distance during that mandatory burn. They don’t call them *miles* per gallon fer nothing’!

Interesting though that you’re not seeing that (kicking in for added torque). Perhaps it doesn’t start doing so until the battery has depleted to a certain point (guessing)?