Driving in EV mode.

[ChangeAgent]

I have the UX250h for a few months now and have never been able to drive in EV mode.  I know what is stated in the manual and all the circumstances where EV mode will not work etc.  See pic. 

 However, I am now slowly getting concerned about there being something wrong or the Battery not getting charged fully.

 Does anybody have similar experiences?  Tips or tricks?

[Zotto]

EV mode is not a permanent state, and it has not to be used excepts for necessity as it discharge rapidly HV Battery, you have to let it charge, mainly during regenerative braking, and then you will notice EV working when re-accelerating while driving at low speed keeping  power indicator in ECO zone.

Let the HSD system decide and initially you can have better results in ECO mode, when you will be more accustomed to hybrid driving you will be able to have EV also in Normal or Sport mode (but always at low speeds and with a light pressure on pedal). 

[ColinBarber]

23 minutes ago, ChangeAgent said:

Does anybody have similar experiences?  Tips or tricks?

The UX doesn't seem to like being put in EV drive mode, unlike older Toyota/Lexus hybrids, as it seems to nearly always be unavailable. What I have found though it that the vehicle doesn't just automatically start the petrol engine after a few seconds after it is put in Ready mode like older hybrids so there isn't a real need for EV drive mode anyway when all it is really meant for is to allow you do move the vehicle out of a garage without causing exhaust fumes which the UX will do anyway.

Seems to be by design but maybe there will be a firmware update at some point. Worth mentioning it to your dealer at next service - the more feedback Lexus get the more they may improve it.

[NemesisUK]

My second RC300h will wait much longer before starting the ICE when put into Ready state. The first one would crank the ICE almost immediately

[Zotto]

8 minutes ago, NemesisUK said:

My second RC300h will wait much longer before starting the ICE when put into Ready state. The first one would crank the ICE almost immediately

You can force ICE starting pressing pedal after entering ready state.

[NemesisUK]

In the winter months the ICE starts almost immediately, summer it waits a good amount of time, plenty for me to disappear down the road!

I just let the car do what it thinks best...

That all said I'm sure when the ICE cold starts it doesn't immediately power the wheels, perhaps to let the fluids circulate before putting load on the engine?

[Las Palmas]

We usually get around in parking places in supermarkets etc. when driving slow (not places to go fast anyway) with EV light on.

Believe Toyota knows when it is best for Battery to be in whatever mode the car use.

[ChangeAgent]

Thanks for answering folks.  I am just worried the Battery is not charging properly and that this is why the EV mode is not available when I leave the garage.

[ColinBarber]

40 minutes ago, ChangeAgent said:

Thanks for answering folks.  I am just worried the battery is not charging properly and that this is why the EV mode is not available when I leave the garage.

If your hybrid Battery is low then you cannot select EV, that is normal, and it is also normal for the hybrid Battery to be low from time to time.

More often than not I get the more generic EV mode is not available at the moment message when the hybrid Battery has plenty of charge. Just seems to be to the way the hybrid system has been tweaked on the UX.

[ChangeAgent]

3 hours ago, ColinBarber said:

If your hybrid battery is low then you cannot select EV, that is normal, and it is also normal for the hybrid battery to be low from time to time.

More often than not I get the more generic EV mode is not available at the moment message when the hybrid battery has plenty of charge. Just seems to be to the way the hybrid system has been tweaked on the UX.

Thanks.  I understand, low is low.

Maybe it is indeed the way it is tweaked.  Will anyway mention it at the service as suggested above, 

[EvilRacer329]

I’ve done some experiments over the last year. It’s worth bring up the Battery charge indicator on-screen. 3 bars (or lower, though I’ve never seen that!) and the engine fires up, no matter what. Beyond that I can ‘force’ EV mode, but it takes very little speed or throttle application for it to drop out. Interestingly, the higher the Battery level, the more speed and throttle I can use in EV mode before it stops out. If the Battery has a high level of charge I can stay in EV mode at slightly higher speeds before it drops back out and fires up the motor.

Ive found the Battery chargers best when driving enthusiastically - accelerating quite hard and then coasting back down to charge up again. Even better are long hills you can regen all the way down!

Nick

[ChangeAgent]

10 hours ago, EvilRacer329 said:

It’s worth bring up the battery charge indicator on-screen.

Thanks.  What do you mean by this?

10 hours ago, EvilRacer329 said:

3 bars (or lower, though I’ve never seen that!)

I usually have 3 bars seldom more.  anybody has more?  

[Spacewagon52]

Very interesting thread. Even after owning the 400h for a year, I find the technology fascinating. My Battery indicator sometimes shows full after I have been driving for a while on main roads. I also find the car will run in EV mode for longer and at higher speeds if the Battery is well charged. 

As in any car, a gentle right foot seems to afford the best economy. Getting around 30 mpg from a 3.3 V6 engine is more than acceptable to me.

Edited August 9, 2021 by Spacewagon52
Missed words

[Thackeray]

2 hours ago, ChangeAgent said:

I usually have 3 bars seldom more.  anybody has more?

I have the third generation hybrid system on the IS and the UX has the fourth generation so there may be differences. That said, I have found that if the car is stationary in the Ready mode and the engine warm, the Battery will go down as far as 40% charge (two bars on the dashboard display) and then the engine will start. When the Battery reaches 50% (three bars) the engine stops and the Battery charge starts to decline and the process repeats.

By contrast, if I have cruise control on at 70mph the car computer keeps the Battery charge at almost exactly 60% (I think that will be around five bars) if the road is flat and I don't press any pedals.

I've only ever seen eight bars a couple of times (this represents 80%) and it tends to happen on very long downhill stretches where regeneration is continuous for several minutes. But the computer will take action to prevent it going above 80%. Initially, the engine may be off as you start going down hill. But to avoid excessive charging, at some point the engine will start to spin without fuel. It sounds as though it's running normally but it's actually acting as a load to draw excess electricity from the Battery. On one of these occasions, when I got to the bottom of the hill I stopped at red traffic lights and was surprised to hear the engine start up while the car was stationary. Usually, the engine stops when the car is stationary. In fact, the electric motor was spinning the engine as a load to use up excess power from Battery and keep it below 80%. It sounded as though the engine was running but in fact no fuel is used when it does this.

You might be interested in this discussion on a Toyota forum. Someone is asking why EV mode can't be engaged. It's about the third generation hybrid system but the main principles are likely to be the same.

 

[ChangeAgent]

very interesting and useful indeed, the link, thanks for that William.  also your post also helps to understand more of what is happening with our computer on wheels.

Edited August 9, 2021 by ChangeAgent

[Brian R]

I can well understand your concerns Ej and perhaps to put your mind at rest you should pop into your local Lexus dealer and ask for a hybrid Battery check. I seem to recall a check is circa £59 or free if done during a service.  Takes about 1/2 hour to complete and thereafter you'll know if there is anything fundamentally wrong, or you need a chill pill.

 

[dublet]

As far as I understand it the hybrid batteries in these are too small to offer any meaningful EV only distance. They're only Nickel batteries and (relatively) small to keep weight down. I'd see the "EV mode" button as a slight gimmick, nothing more.

[ColinBarber]

2 hours ago, Thackeray said:

I have the third generation hybrid system on the IS and the UX has the fourth generation so there may be differences.

The whole generation thing is a bit of marketing nonsense to be honest as each new model has differences even within the 'generation' but there certainly are noticeable differences between the IS and UX.

I find the UX Battery assists the petrol engine much more than the IS (or a 4th gen Prius) when it would drop into EV mode more often.

EV drive mode seems to be nearly always unavailable when it would be in an IS or Prius 4.

18 minutes ago, dublet said:

I'd see the "EV mode" button as a slight gimmick, nothing more.

It's really just for moving in/out of the garage without the petrol engine having to fire up - it shouldn't really be used in normal driving - it is less efficient to do so than just letting the system do its own thing.

[NemesisUK]

25 minutes ago, dublet said:

I'd see the "EV mode" button as a slight gimmick, nothing more.

These "self-charging" hybrids are a 'stop-start' system on steroids. As already mentioned the EV mode is only for car park manoeuvres, or at the most, silent exits in the early mornings.

Just let the car do it's own thing, the programmers at Toyota know more about getting the most (economy) from the car than 99% of drivers

[dublet]

11 minutes ago, NemesisUK said:

As already mentioned the EV mode is only for [..] at the most, silent exits in the early mornings.

How can one have a silent exit when you have to shout "ENGAGE, AHEAD WARP FACTOR 1" at the top of your voice?!

[ChangeAgent]

1 hour ago, Brian R said:

I can well understand your concerns Ej and perhaps to put your mind at rest you should pop into your local Lexus dealer and ask for a hybrid battery check. I seem to recall a check is circa £59 or free if done during a service.  Takes about 1/2 hour to complete and thereafter you'll know if there is anything fundamentally wrong, or you need a chill pill.

 

I will do that, good tip.  my service is soon so do it then.  

[Zotto]

Just a point I have forgotten to write: to stay in EV  mode, you have to keep your  power gauge BELOW mid of ECO zone, else system sees that you are requesting more power and switches on thermal engine. You can see there is a  sign in ECO scale that is the thermal engine engage point.

[ChangeAgent]

2 minutes ago, Zotto said:

You can see there is a  sign in ECO scale that is the thermal engine engage point.

I did not know this will have a look at it next time I am in the car. 

[EvilRacer329]

Interesting discussion. The Battery charge meter I'm referring to is the information display on the big central screen or the one you can bring up in the dashboard that shows how fully-charged the Battery is. I've managed to get mine fully charged to 100% before now and never noticed the electric motor spinning the engine to waste the power down to 80%. I'm going to have to read up on that.

The electric motor can take you further than you think - Lexus reckon 1.2 miles, and I reckon I've managed that under the right conditions once or twice. If you're trickling through town in heavy traffic below 30mph you can keep the "EV" light on the entire time, rolling along silently. It's great! Forcing EV mode discourages the system from firing up the petrol motor, and does allow you to request a little more throttle before giving up and switching the engine on, but I have noticed that it's charge-dependent. If the Battery has a high state of charge it'll tolerate a slightly heavier throttle before giving in. Most of the time though the results are the same as just leaving the car in Drive and being gentle with your right foot.

The most reliable way to test charging your own Battery is to fire up your car on a cold morning and leave it idling in the driveway until the engine warms up and shuts off. If you have the climate control disabled there will basically be no draw on the traction Battery and your engine will be acting purely as a generator. I recently did this with my aircon on because I'd washed the car somewhat enthusiastically and needed to get the damp out of the cabin with the air-con. By the time the engine had warmed up (just a couple of minutes) my Battery was at 80% or so.

If you're driving it like a normal car you'll see some benefits (engine shutting down during coasting) but you'll also find that your Battery is used more heavily to haul your car up to speed. On the motorway the system will cycle back and forth automatically between charging the Battery a little bit to letting the engine rev lower and using the recently-gained charge to make up the shortfall, keeping the overall power output the same and maintaining your requested speed. If you brake earlier and more gently, keeping as much care as you can to only brake hard enough to just fill up the regen gauge on the dashboard you'll find you recoup more electricity for the Battery. I usually find that I can drive all the way through my housing estate on electric only and park the car up in total silence.

Nick

[ChangeAgent]

Thanks Nick.  Amazing you once 100% mine seems to always hang around 3 stripes, maybe 4.