How To Drive Hybrid Cars Rules Of Thumb Guide

[Wayne2015]

Hi. Let's say. It's minus 5 outside, the car has frozen over. I get in, start, wait for ready mode, turn on all heating full including ac. The engine starts. I then wait for the engine to turn off before driving away. Yes/ no?

A normal day. Same as above, perhaps less heating. Wait or not?

The point I am trying to make is. If it is really cold, would it not take some considerable time for the engine to turn off?

A case study. 7am the other morning. Got in , pressed start, ready mode on, heating on, engine engaged. Drove 1/2 mile to base, got out of car to chat to colleague, the ice as you call it was still running ten minutes after arriving at base, turned off and turned back on 2 minutes later. Heating still on, as I do like to be warm. My speed getting to the base was around 25 mph, flat terrain, ev flashed maybe once.

As you can tell I am still pretty confused.

That's a good point, as when the heat is on, the ICE will run longer to warm up to a higher temp, so after the ~50 sec when it moves to stage 2 then ICE remains running.

Also when the OAT is 10℃ or less, you could wait 50 or so seconds (say you need to clear the windscreen/rear window, e. g.) but other than that, there is not much to be gained by waiting longer.

In Cliff's case, his hybrid is a working vehicle, so time being money, waiting around is not the best idea, so he would be just as well to get the car READY and drive off. If you get to base and the ICE (internal combustion engine) is still running and there is no good reason to leave the car running switch it off.

Hope that helps.

What is OAT?

[MEP's Yaris GS]

Hi. Let's say. It's minus 5 outside, the car has frozen over. I get in, start, wait for ready mode, turn on all heating full including ac. The engine starts. I then wait for the engine to turn off before driving away. Yes/ no?

A normal day. Same as above, perhaps less heating. Wait or not?

The point I am trying to make is. If it is really cold, would it not take some considerable time for the engine to turn off?

A case study. 7am the other morning. Got in , pressed start, ready mode on, heating on, engine engaged. Drove 1/2 mile to base, got out of car to chat to colleague, the ice as you call it was still running ten minutes after arriving at base, turned off and turned back on 2 minutes later. Heating still on, as I do like to be warm. My speed getting to the base was around 25 mph, flat terrain, ev flashed maybe once.

As you can tell I am still pretty confused.

That's a good point, as when the heat is on, the ICE will run longer to warm up to a higher temp, so after the ~50 sec when it moves to stage 2 then ICE remains running.

Also when the OAT is 10℃ or less, you could wait 50 or so seconds (say you need to clear the windscreen/rear window, e. g.) but other than that, there is not much to be gained by waiting longer.

In Cliff's case, his hybrid is a working vehicle, so time being money, waiting around is not the best idea, so he would be just as well to get the car READY and drive off. If you get to base and the ICE (internal combustion engine) is still running and there is no good reason to leave the car running switch it off.

Hope that helps.

What is OAT?

Outside Air Temp I believe.

[PeteB]

Does it not reduce the amount of power delivered during the first half of the pedal travel compared to normal mode?

NORMAL Mode?

What is NORMAL Mode?

Compared to which? EV? ECO?

If you're in ECO mode and press the ECO button again (or you're in PWR and press PWR) no mode lights are on and you're in NORMAL mode. In this mode the accelerator response is linear and there's no adjustment to heating and ventilation.

In ECO mode, the accelerator response is much reduced in the first half of its travel and then builds up more rapidly to full power on the second half (but apparently not on the plugin). It's also useful in slippery conditions to give better control.

In PWR mode the throttle comes on strong very early in it's travel range, and gives something like 75% power at the halfway point.

EV mode can be selected in any of the three above modes provided the other conditions are right (speed, Battery level, temperature etc).

[MEP's Yaris GS]

In ECO mode, the accelerator response is much reduced in the first half of its travel and then builds up more rapidly to full power on the second half (but apparently not on the plugin).

I'll have a play on the way to work tomorrow but am certain no throttle difference on my plug in.

I assume if at half throttle accelerating away and I take it out of eco mode I should notice a clear increase in power to the wheels without having moved my foot on the throttle?

[Wayne2015]

Does it not reduce the amount of power delivered during the first half of the pedal travel compared to normal mode?

NORMAL Mode?

What is NORMAL Mode?

Compared to which? EV? ECO?

If you're in ECO mode and press the ECO button again (or you're in PWR and press PWR) no mode lights are on and you're in NORMAL mode. In this mode the accelerator response is linear and there's no adjustment to heating and ventilation.

In ECO mode, the accelerator response is much reduced in the first half of its travel and then builds up more rapidly to full power on the second half (but apparently not on the plugin). It's also useful in slippery conditions to give better control.

In PWR mode the throttle comes on strong very early in it's travel range, and gives something like 75% power at the halfway point.

EV mode can be selected in any of the three above modes provided the other conditions are right (speed, Battery level, temperature etc).

Cheers Pete!!! :)

I asked that question before and couldn't find answers in the manual....

That is "what mode is my car in as I not pressed any EV , ECO nor PWR button???"

U answered my question now :) :) :)

So I ALWAYS been in NORMAL mode then - lol

Hmmmm...with 52mpg in my first tank test.

If I press the ECO mode I should get better mpg and slight lost in performance than normal mode?

[PeteB]

...If I press the ECO mode I should get better mpg and slight lost in performance than normal mode?

Only if you don't press the pedal harder to make up for it (although the changes to H&V might still help a bit) :D

[Wayne2015]

...If I press the ECO mode I should get better mpg and slight lost in performance than normal mode?

Only if you don't press the pedal harder to make up for it (although the changes to H&V might still help a bit) :D

H&V?

[PeteB]

In ECO mode, the accelerator response is much reduced in the first half of its travel and then builds up more rapidly to full power on the second half (but apparently not on the plugin).

I assume if at half throttle accelerating away and I take it out of eco mode I should notice a clear increase in power to the wheels without having moved my foot on the throttle?

Yes. You're more likely to notice if you select ECO from NORMAL with about ¼ pedal travel.

I must say I was surprised when you said it didn't do it on the PiP as I'd have thought it would have stuck in my mind when I had one for a day a couple of years ago, given I use ECO all the time.

[PeteB]

...If I press the ECO mode I should get better mpg and slight lost in performance than normal mode?

Only if you don't press the pedal harder to make up for it (although the changes to H&V might still help a bit) :D

H&V?

sorry - Heating & Ventilation

in ECO, it may run the engine or A/C a little less and the fan a little slower and try slightly less hard to maintain the requested temperature

[Wayne2015]

...If I press the ECO mode I should get better mpg and slight lost in performance than normal mode?

Only if you don't press the pedal harder to make up for it (although the changes to H&V might still help a bit) :D

H&V?

sorry - Heating & Ventilation

in ECO, it may run the engine or A/C a little less and the fan a little slower and try slightly less hard to maintain the requested temperature

Wait

This was my original confusing....

If I press the ECO button....

What is the actual difference WHEN in NORMAL mode and I tend to be in the ECO bands with the ECO light automatically on???

And what is the difference when in ECO mode, but car is in the PWR bands?

[johalareewi]

The modes behave differently across the Toyota Hybrid range.

My gen3 Prius has ECO, NORMAL and PWR (plus EV).

The difference between the modes is the accelerator pedal mapping.

There is no difference to the actual power available to drive - You just have to move the pedal further.

Also when in ECO mode, the system throttles back the aircon and doesn't fire the ICE as much in stationary traffic.

My wife's gen1 hybrid Yaris has ECO and NORMAL (plus EV).

ECO mode in the Yaris is somewhere between my NORMAL and PWR modes in accelerator pedal response.

I have no idea what ECO mode does to the aircon and ICE.

ECO mode in the Prius is nothing like ECO mode in the Yaris.

Just saying...

[PeteB]

Wait

This was my original confusing....

If I press the ECO button....

What is the actual difference WHEN in NORMAL mode and I tend to be in the ECO bands with the ECO light automatically on???

And what is the difference when in ECO mode, but car is in the PWR bands?

ECO, EV, & PWR mode on the top part of the speedo display means that mode has been selected by the driver.

The ECO & EV symbols that appear on the HSI (Hybrid System Indicator) and HUD (Head up Display) tell you what the car is actually doing, and are independent of the driver-selected mode. Some examples:

• in ECO Mode but HSI is in PWR area (right or top of gauge) - ECO symbol goes out
• car is running on electric only and engine is off - EV symbol lights up *
• car is in NORMAL or PWR mode but you're accelerating very gently (HSI in left half) - ECO symbol lights up

Hybrids with the 1.8 litre petrol engine tend to have ECO, PWR & EV buttons (except PiP), Yaris Hybrid (1.5 litre) just has ECO and EV - I too struggle to notice any difference in ECO mode on the Yaris.

* Note that under light load and good HV Battery charge the cars sometimes run electric only at higher speeds, but above around 45 mph (1.8) or 42 mph (1.5) the petrol engine will be turning (just to keep the Motor Generators within prescribed RPM limits) but not burning fuel - in this state the EV symbol doesn't light up, but the instant mpg reading will be off the scale. If you're sensitive, you can feel a very slight tremor at the 45/42 mph boundary when slowing down without braking as the petrol engine stops.

[YarisHybrid2016]

In the Yaris, the ECO MODE has a distinct effect on throttle response.

Quick example.

Normal mode:

* idle/coasting

* middle of ECO

* top of ECO

* middle of power

* top of power

ECO mode:

* idle/coasting

* 1/3 of ECO

* 2/3 of ECO

* top of ECO

* top of power

It also limits AC fan RPM and reduces AC power output (so it takes longer to cool/warm).

Regarding the ICE warm-up: I have found that after the car is started and READY light is on, that if I push the accelerator in P, it will cause the ICE to start. Will this cause it to run in the warm-up mode? I have found by accident that the fuel economy seemed to be better by letting the ICE run like this first, waiting for it to stop, then driving (if I know I will be using it). I have yet to try this again (rather than simply waiting for READY).

I have also noticed in town (30 MPH) that if the ICE is running, that the RPM will increase during what I can only assume is a period to charge the Battery where the engine was only idling previously. I'm wondering now if the engine RPM is also higher during the beginning of a journey if driving and using the ICE in its warm-up period, which is why fuel economy is low at this point?

If that's the case, then if going on a journey that is sure to cause the ICE to start, allowing it to complete the warm-up cycle whilst stationary seems to be the best option regarding fuel economy (given that the whole warm-up process is optimized precisely to get the ICE warmed up). It is able to run at the lowest RPM, and it doesn't have cold air blowing around it whilst it warms up.

EDIT: Having actually driven a hybrid for a while, Joseph's link (post #9) makes a lot more sense. Given that the Yaris Hybrid is supposed to be just a smaller Prius system in basic operation, I'll try some of the suggestions in the link and see what happens. I certainly recognize all the apparent states that he talks about (they seem to be most noticeable if the car is cold and driving around town, particularly when it comes to the S3a/S3b states).

I have also found times where the car has been running a while, the HV Battery has good charge, yet it won't enter EV mode by lifting off (or the EV light will flicker on then off, then come on later by itself). It has the same behavior as if the HV Battery is low on charge, yet it isn't.

[Wayne2015]

Wait

This was my original confusing....

If I press the ECO button....

What is the actual difference WHEN in NORMAL mode and I tend to be in the ECO bands with the ECO light automatically on???

And what is the difference when in ECO mode, but car is in the PWR bands?

ECO, EV, & PWR mode on the top part of the speedo display means that mode has been selected by the driver.

The ECO & EV symbols that appear on the HSI (Hybrid System Indicator) and HUD (Head up Display) tell you what the car is actually doing, and are independent of the driver-selected mode. .

That's for the Prius, isn't it Pete?

My Auris has the MODE selected on the left of the PWR Dial

And the current driving mode on the right of the PWR dial

So the Prius can be on electric only at 20+?????

I tested mine Auris - by looking at the DISPLAY which shows if either the electric or the engine or both is powering the wheels......if :

1. I select EV mode -

It will revert to Engine running wheels IF I put my foot down OR go above 20mph

2. If I select EV mode and SLOWLY go above 20+ it will show engine running wheels

3. If II select NORMAL mode go above 20+ and then select EV mode - it will not let me :(

4. Though in any mode, if I drive 20+ (upto 35mph?) VERY slowly it will show electric running wheels

Or have I got that completely wrong????

DISPLAY just shows whether engine or Battery powering wheels and NOTHING to do with electric motoring being in/off mode?????

[MEP's Yaris GS]

the petrol engine will be turning (just to keep the Motor Generators within prescribed RPM limits) but not burning fuel

Actually with the HSD setup, it does burn fuel when ever its turning, I've never managed to really induce an overrun to create fuel shut off, however its such a small amount which is why the MPG shows max.

[PeteB]

the petrol engine will be turning (just to keep the Motor Generators within prescribed RPM limits) but not burning fuel

Actually with the HSD setup, it does burn fuel when ever its turning, I've never managed to really induce an overrun to create fuel shut off, however its such a small amount which is why the MPG shows max.

Maybe it's different on the Gen 3, or PiP - on the Gen 1 Prius you could buy an accessory from a firm in the US that showed a couple of extra LEDs in the speedo housing - one lit red when the real real brakes came on, and the other lit green when the engine was off.

When I managed a fleet of a couple of hundred Prius a techie from Toyota told me that in this state the Variable Valve Timing shifted to an extreme where there was virtually no compression in the cylinders (did this when restarting the engine too). I haven't had time to test this out on my current Gen 3 with the Torque displays, but also note that the Energy Monitor display shows no red arrows for the engine under these circumstances.

I wonder what other differences there are in the PiP, since it can do EV mode up to 60 mph? Presumably, the engine isn't turning, is it?

[PeteB]

That's for the Prius, isn't it Pete?

My Auris has the MODE selected on the left of the PWR Dial

And the current driving mode on the right of the PWR dial

So the Prius can be on electric only at 20+?????

I tested mine Auris - by looking at the DISPLAY which shows if either the electric or the engine or both is powering the wheels......if :

1. I select EV mode -

It will revert to Engine running wheels IF I put my foot down OR go above 20mph

2. If I select EV mode and SLOWLY go above 20+ it will show engine running wheels

3. If II select NORMAL mode go above 20+ and then select EV mode - it will not let me :(

4. Though in any mode, if I drive 20+ (upto 35mph?) VERY slowly it will show electric running wheels

Or have I got that completely wrong????

DISPLAY just shows whether engine or BATTERY powering wheels and NOTHING to do with electric motoring being in/off mode?????

I've only driven several hundreds of miles in Auris Hybrids, as opposed to 167k/50k/45k in Gen 1/2/3 Prius respectively (and a few thousand in Lexus and Honda Hybrids too), so whilst I can speak with a fair degree of confidence (but certainly not infallibility) about the first three versions of Prius, my knowledge of others is, shall we say more suspect.

That said, I think the Auris behaves pretty much like a Gen 3 Prius - EV mode and running on electric only are not quite the same thing - whilst it is electric only when in EV mode, it can run on electric only at other times when the circumstances allow it.

1. I think you'll find that you can go EV up to 30 (or somewhere between 20-30) if the engine in hot enough plus the inverter and HV Battery temperatures are within the range that permits higher EV speeds.

2. as above

3. It might when running warm and electrics are not too hot (up to 30)

4. If there's enough charge in the HV Battery, temperatures are within allowed ranges and you stay in the bottom half (Auris/Yaris) / left half (Prius) of the ECO band on the Hybrid System Indicator it will try to use electric only.

The Energy Monitor display updates at least once a second but I think it's still true that they hybrid system changes state more quickly than the display can tell, so different things may happen in between - the Gen 1 Prius display only refreshed every 2 seconds (it was right up against the limit of what 16 bit computing of the 1990s could cope with!) so it only showed a snapshot of what was going on.

The EV indicator (as opposed to the "EV Mode is selected" light) is the nearest thing to gospel regarding electric only running.

[MEP's Yaris GS]

I wonder what other differences there are in the PiP, since it can do EV mode up to 60 mph? Presumably, the engine isn't turning, is it?

Not in EV, but in HV it'll stick to the 45MPH rule like the normal Gen 3. Well, if ICEis running it won't shut off unless you hit <45MPH or are below 60 and hit EV. In HV with ICE off you can get to 49MPH, and ICE kicks in at 50MPH.

[AMAQ03]

Hi. Let's say. It's minus 5 outside, the car has frozen over. I get in, start, wait for ready mode, turn on all heating full including ac. The engine starts. I then wait for the engine to turn off before driving away. Yes/ no?

A normal day. Same as above, perhaps less heating. Wait or not?

The point I am trying to make is. If it is really cold, would it not take some considerable time for the engine to turn off?

A case study. 7am the other morning. Got in , pressed start, ready mode on, heating on, engine engaged. Drove 1/2 mile to base, got out of car to chat to colleague, the ice as you call it was still running ten minutes after arriving at base, turned off and turned back on 2 minutes later. Heating still on, as I do like to be warm. My speed getting to the base was around 25 mph, flat terrain, ev flashed maybe once.

As you can tell I am still pretty confused.

The prius does not have a coil for heating, it uses the ICE to generate heat for your cabin. As long as you have the heater on inside your car cabin (AC heater) the gas engine or ice will turn on much more frequently to generate heat to be supplied to heat your cabin

[MEP's Yaris GS]

Hi. Let's say. It's minus 5 outside, the car has frozen over. I get in, start, wait for ready mode, turn on all heating full including ac. The engine starts. I then wait for the engine to turn off before driving away. Yes/ no?

A normal day. Same as above, perhaps less heating. Wait or not?

The point I am trying to make is. If it is really cold, would it not take some considerable time for the engine to turn off?

A case study. 7am the other morning. Got in , pressed start, ready mode on, heating on, engine engaged. Drove 1/2 mile to base, got out of car to chat to colleague, the ice as you call it was still running ten minutes after arriving at base, turned off and turned back on 2 minutes later. Heating still on, as I do like to be warm. My speed getting to the base was around 25 mph, flat terrain, ev flashed maybe once.

As you can tell I am still pretty confused.

The prius does not have a coil for heating, it uses the ICE to generate heat for your cabin. As long as you have the heater on inside your car cabin (AC heater) the gas engine or ice will turn on much more frequently to generate heat to be supplied to heat your cabin

No - this will only be the case if the ICE doesn't run enough in normal usage to supply the requested heat. My ICE is on no more on my commute with the heater on or off because most of my journey is with the ICE running anyway.

[PeteB]

Case in point, for some years when I had my last Mk 1 Prius I had a 40 mile each way cross country commute to work, with some longer journeys thrown in.

Because the warm-up period represented such a small percentage of my driving, my winter/summer mpg showed almost no variation. If the windows were clear, I drove off as soon as READY appeared, if they were fogged or iced, I ran the engine whilst clearing them.

Currently, my Gen 3 gets noticeably worse in colder weather as I do few long journeys and many more short ones.

[timberwolf]

Hi. Let's say. It's minus 5 outside, the car has frozen over. I get in, start, wait for ready mode, turn on all heating full including ac. The engine starts. I then wait for the engine to turn off before driving away. Yes/ no?

A normal day. Same as above, perhaps less heating. Wait or not?

The point I am trying to make is. If it is really cold, would it not take some considerable time for the engine to turn off?

A case study. 7am the other morning. Got in , pressed start, ready mode on, heating on, engine engaged. Drove 1/2 mile to base, got out of car to chat to colleague, the ice as you call it was still running ten minutes after arriving at base, turned off and turned back on 2 minutes later. Heating still on, as I do like to be warm. My speed getting to the base was around 25 mph, flat terrain, ev flashed maybe once.

As you can tell I am still pretty confused.

The prius does not have a coil for heating, it uses the ICE to generate heat for your cabin. As long as you have the heater on inside your car cabin (AC heater) the gas engine or ice will turn on much more frequently to generate heat to be supplied to heat your cabin

Searching online suggests that the Prius has two electric PTC heaters but that the main source of heat is from the ICE.

[MEP's Yaris GS]

Hi. Let's say. It's minus 5 outside, the car has frozen over. I get in, start, wait for ready mode, turn on all heating full including ac. The engine starts. I then wait for the engine to turn off before driving away. Yes/ no?

A normal day. Same as above, perhaps less heating. Wait or not?

The point I am trying to make is. If it is really cold, would it not take some considerable time for the engine to turn off?

A case study. 7am the other morning. Got in , pressed start, ready mode on, heating on, engine engaged. Drove 1/2 mile to base, got out of car to chat to colleague, the ice as you call it was still running ten minutes after arriving at base, turned off and turned back on 2 minutes later. Heating still on, as I do like to be warm. My speed getting to the base was around 25 mph, flat terrain, ev flashed maybe once.

As you can tell I am still pretty confused.

The prius does not have a coil for heating, it uses the ICE to generate heat for your cabin. As long as you have the heater on inside your car cabin (AC heater) the gas engine or ice will turn on much more frequently to generate heat to be supplied to heat your cabin

Searching online suggests that the Prius has two electric PTC heaters but that the main source of heat is from the ICE.

Where have you seen that? I'm not aware of the UK market getting this.

[PeteB]

Where have you seen that? I'm not aware of the UK market getting this.

North American Gen 2 Prius (and maybe some other 'cold' territories) had two electric heaters (and a mechanism that sucked hot water into a very efficiently insulated flask when the car was switched off and pumped it back in again next time the car was started!).

None of this made it to the Gen 3, and I've not heard of any other Toyota Hybrids getting the electric heaters.

I'd have thought they would have made a lot of sense in the PiP.

[MEP's Yaris GS]

I'd have thought they would have made a lot of sense in the PiP.

Not really, as the heated seats are more than adequate. What would have been better is a heated front screen (and possible steering wheel) to prevent the requirement of ICE start up if screen needs clearing etc.