2018 Prius Prime - Remote Engine Start

On my Gen 4, turning on Defrost seems to force the engine on, but I do not have a heat pump like the Prime..

 

prime is the same, but does defrost come on in the morning if you leave it on at night, or is it auto shut off?

 

MAX defrost (the dedicated button) will shut off automatically. This forces the engine to start and run periodically.

Regular defrost (the climate-control blower setting) is retained. This takes advantage of electric-only operation.

 

will any settings guarantee engine start with a full traction battery, regardless of outside temp?

 

No, I don't think so. Only when extremely cold, like near 0F or below, ICE will come on regardless of the heat setting. At below 14F, if you keep the heat ON, ICE will come on. Meaning above 14F, the only way to force the ICE to come on is to keep the traction battery not charged.

 

As previously noted, engine warmup is not required or desired. In my opinion, you are wasting your money to install an aftermarket system that does something that doesn't need to be done. And may cause you warranty problems in the future.
But, it's your money.

 

On page 99 of the 2018 Prime owner manual, the following statement appears at the end of the page:

"◆ Warming up before driving

Since the gasoline engine starts up and cuts out automatically, warming up is not necessary."​

But, if the engineers who designed the car don't convince you, there are any number of websites that discuss this issue: Car Talk, AAA, etc. Here is the snippet from AAA, the others read pretty much the same.

"Want to know if you really need to warm up the car engine before driving, even during the cold winter months? AAA provides auto care tips that help you keep your vehicle running smoothly every season of the year.

Myth: To improve performance, particularly in cold weather, allow the engine to run for a few minutes before driving.

Fact: Start the engine and allow it to idle only for the time it takes you to fasten your seat belt. This ensures that lubricating oil gets to all of the engine's vital parts. Driving the car normally and avoiding hard acceleration brings the engine to a warmer temperature faster, and also reduces wear and exhaust emissions. Naturally, a little longer idle time is ok in winter while you clear snow and ice from the windshield and other car parts."​

 

Old Habits Die Hard

 

You should be convinced now. The advice applies in all climates - the car never requires an idle warmup.

 

does the 08 lexus require synthetic oil?

 

What will you be testing? Page 48 of your 2008 Lexus manual says:

"Warming up before driving
Since the gasoline engine starts up and cuts out automatically when cold, warming up the engine is unnecessary. Moreover, frequently driving short distances will cause the engine to repeatedly warm up, which can lead to poor fuel economy"
​

Note that an idling engine gets zero mpg.

 

You sure the ct200h is from 2008?

 

If you want to test, get the Android app Hybrid Assistant, which will show you your temperatures. There is a companion app called Hybrid Reporter that summarizes each trip and graphs data, provides summaries, etc. One of the things it can report is time to temperature, particularly engine coolant temperature. Here is an example of the start of a recent road trip. Started the car in EV mode, drove through town to the interstate on EV and shortly before I got to the Interstate shifted to HV. As you can see, the car warms very quickly. And, there isn't a huge difference when it's colder outside - the grille shutters are closed and the engine warms quickly.

 

No. Completely separate from the car and its software. I run it on an old Samsung tablet. The software is shareware and the specific OBD adapter it likes was less then $40.