Scenario: It's cold (say 10 F°) I have a 30 mile highway commute. I start off in EV and get on the highway and set my cruise to 70 mph. Once EV mode is depleted, ICE kicks in at 70 mph. Any concerns starting an engine like that? I've always been told to let a cold engine idle for a few seconds first to make sure all the parts (including the upper part of the engine) is well lubricated first.
i'm sure the car is designed to protect itself in all conditions. that being said, i try to warm the ice before i need it, just being cautious, it's my nature. the other thing is, in protecting itself, it's not going to let you have full power if you need it until it's warmed up to some point. if you were to hit a steep grade when the ice kicked, you might find yourself in the right lane going slower and slower.
Once you get to about 62mph, the ICE will kick in, even in EV mode. In this so-called "EV-Boost" mode, the battery is providing most of the power, but the ICE is turning (and warming up if necessary). You can tell if you are in this mode if you have a empty outline of a car over the power bar. So in your 70mph scenario, long before the battery is depleted, the ICE is warmed and ready to go.
+1 to CharlesH post. In the case how you described your commute, ICE would be at normal operating temp (~190 deg F) when the PHV battery is depleted. That's because both the battery and ICE will be used above 62 mph speed.
Okay, 70 was a bad example. Let's change the scenario to 60 mph. The point of the question is if a very cold engine can start and do highway speed.
This has been discussed before, so you might search for those discussions. I think your concern is that if you cold start at 100kph in extreme cold weather, will you run the risk of overrevving an unlubricated engine. I can only say from some cool (but not cold) weather experience, that the rpm stays under 2k. Even when I step on it, the rpm generally doesn't go over 3k. Since the engine oil is 5-30, cold weather lubrication shouldn't be an issue. So even if you started up out of the driveway, your engine speed is what is most important, not the vehicle's speed. The VRT is pretty good at keeping the engine in a range that won't burn it or freeze it up.
When you depleted the EV miles, the HV battery portion is still nearly full (I think 8/8 battery block). So, PiP can still use the HV portion to support the ICE warm up. ICE will start and rev around 1,500 rpm during the warm up at 60 mph. During that time, the battery power will fill in, to prevent ICE from working above the target load.
Come to think of it, when the ICE kicks into HV mode, it displays 0.7 EV miles remaining. I think that's the reserve for ICE warm up.
Mine stays in EV mode till it reaches 0 miles. The battery icon does change at 0.7 from solid to bars but remains in EV mode till 0 miles at which I feel ICE kick in.
also, in general, i think these concerns about "warming up the engine" were valid in vehicles manufactured 2 decades ago. modern engines and emissions systems do a lot of things to make sure that engine warmup is as efficient, non-taxing, and emissions-free as possible.
When you get below 0.7 miles of EV, the battery icon changes from solid to the familiar 8 segment battery icon. You are still in EV mode, however. HV mode doesn't kick in until you have 6 battery bars showing. At that point SOC is at 23.1%.
No worries. The engine is spun up before fuel and spark are applied, so it is fully lubricated before it starts running on its own.
Using a Gen 1 PSD simulator (I can't find a more recent one) the engine only has to be doing 1200 RPM at 70 MPH, almost idle. For 60 MPH, it is under idle 780 RPM. Toyota Prius - Power Split Device
