Predictive EV drive experiences

This is going to have the Americans feeling a bit left out, but as Europeans are starting to get the car, how is the Predictive EV Drive looking? Let's share experiences, observations and tips.

I've only had one chance to give it a go, the other evening - had to give a lift maybe a dozen kilometres away - twice, there and back.

Starting the last round trip at about 34%, and arriving with 11% at the destination, it was clear we weren't making it back on EV.

So, destination set, AUTO HV/EV mode selected, off we went home.

And it sat firmly in EV for quite a while - it wasn't interested in starting the engine, even when pulling out quite fast onto a 80km/h section. Charge edged down towards 5%. Range anxiety started to set in, as it occurred to me we didn't actually know if the engine worked. Had anyone tested it since Japan? Was it ever going to start?

Apparently knew what it was doing, as it decided the time to start the engine was as we entered the entry ramp to a 100km/h motorway. Not in response to the acceleration, as we weren't accelerating as hard as onto the previous 80km/h bit - it seemed to recognise we were just about to hit the fastest part of the trip.

And it did the first 3/4 of the motorway segment on HV, at 5% SoC, before deciding we were close enough, and doing the last 1/4 on EV, winding to about 2% as we left the motorway, with a couple of kilometres to go. And it held EV the rest of the way until it ran out, hitting "---" SoC and switching to HV with about 500m to go.

Seemed like a slight miscalculation, but on reflection the aim IS to use as much electricity as possible - you wouldn't want to actually arrive with anything left in the battery. So I guess you're always going to be pulling up in HV mode if using the predictive EV drive on a long trip? If you want to arrive quiet and sneaky you might want to manually select HV before you arrive to save the last few electrons.

I don't know if the car had done any learning, or was working purely on map data - it was the second trip, so I guess it could have learnt something. I think the map is supposed to show something about the learning, but didn't see anything. Maybe with more learning it could hit zero more closely at the destination.

I can see this is going to be a fun thing to observe.

 

I realise I forgot to explain what Predictive EV Drive is to the uninitiated. The main manual says:

Predictive EV Drive
When using route guidance by the navigation system, the system automatically switches between EV driving and HV driving based on data such as the remaining charge of the hybrid battery (traction battery), route and traffic information to ensure that the vehicle efficiently uses electrical energy from the traction battery.

For example, the system switches to HV during high load section such as highway, uphill.​

• The system operates only when AUTO EV/HV mode is selected.

The multimedia manual says:

The system automatically switches between EV driving and HV driving based on data such as the remaining charge of the hybrid battery (traction battery), route and traffic information to ensure that the vehicle efficiently uses electrical energy from the traction battery.

Therefore, enhanced fuel economy is expected.

When the system operates it informs the driver about the benefit on the navigation screen upon arrival at the destination.​

• The system operates only when AUTO EV/HV mode is selected.
  
• The system operates when starting route guidance and the position of vehicle is along the guided route. (The system does not operate in parking lots, etc.)
• When multiple destinations are set, the system will continue to operate to the last destination.

 

On the car system. I'm pretty certain it won't work with the the others - unlikely they're sending the data the system needs; they're just giving the car user interface stuff to show.

Maybe you can leave the car navigation running silently in the background while using the phone's? Might work as long as they select the same route...

(Never quite seen the point of using a phone for car functions myself, so I've got no grumbles.)

 

"Predictive efficient drive" is the term they use for a set of navigation-based functions. There seem to be three:

Everyone (with navigation) has "predictive deceleration support", which I haven't seen yet - I believe that's based on learning good regeneration spots without any need for to manually enter routes. That's in both HEVs and PHEVs.

Then European and Japanese PHEVs have this Predictive EV Drive (it's more directly named "predictive EV/HV mode switching control" in the Japanese manual). I get the impression that there may be regulatory issues (to do with emissions?) about cars getting smart about their engine control algorithms, slowing spread. Didn't the Gen 4 have some of this in Japan, but not elsewhere?

In Japan the HEV has "predictive SOC control", a function that tries to empty the battery when it guesses you're approaching a long-term parking spot - only in colder weather - so it can capture energy during warm-up. That doesn't rely on you telling the car anything, just it learning. That also doesn't rely on manual route entry, but it is partly server-based (for the weather forecast?) and does require the connected service subscription.

 

They're stored by a learning function. The navigation/multimedia manual expands:

Predictive deceleration support

The system automatically stores and registers support points where the driver always decelerates or stops based on pedal operation and the vehicle speed of the driver.

The registered points are shown on the map as icons [leaf] for use as predictive deceleration support points. When the position of the vehicle approaches the registered point, the icon changes to an emphasized [sapling] icon.

Depending on the system or driving situation, the engine brake amount increases after releasing the accelerator pedal.

As a result, the battery charge amount can be increased when decelerating or stopping the vehicle to enhance fuel economy.
​

There's no text suggesting any use of route guidance is required. Whereas there is for Predictive EV Drive.

 

I suspect the "cold weather" may be in Japan terms - I forget their exact phrasing.

Yep, patents could be it. Although the feature is tagged in the Japanese brochure with a "World first" marker! (And without mentioning the weather bit, which is only in the manual).