Hybrid and heavy stop and go traffic

[16_Auris_HSD]

I don't own a Prius but this subforum feels like a better place to discuss Toyota hybrids in general.

My main gripe with my car (16 plate hybrid Auris estate) is what I was hoping to be its main selling point, i.e. how it drives in heavy traffic. The Battery is too small and the regen not strong enough to replenish the energy used by crawling/stopping and moving off. And once it runs on empty the ICE acts as a very aggressive range extender/generator buzzing away like crazy at revs that are far from tickover trying to put more electricity into the pack (and it's quite crap at doing it to be honest). This is more than disappointing from refinement point of view and I must say that when someone asked me what's the point of it if it behaves like this I couldn't answer. The fuel economy isn't that ground breaking and with modern petrol engines being so efficient and refined to the point of not being able to hear them when stationary I don't know what the point of a non plug in hybrids is. And I wish I knew about it before buying one.

I'm curious to read your feedback on this.

[FROSTYBALLS]

25 minutes ago, 16_Auris_HSD said:

I don't own a Prius but this subforum feels like a better place to discuss Toyota hybrids in general.

At one time this particular club was for the Prius and hybrids. However, with the hybrid drivetrain being extended to the Auris, Yaris, Rav4, etc - not to mention grey imports - , it became difficult to manage with some members posting queries within the specific model clubs, some posting in the Prius/hybrid club, and so on.

When the club format was revamped the Prius/hybrid club reverted to being for the Prius, with other hybrids being dealt with in the specific model clubs. 

In future, if a topic is for the hybrid version of either the Auris, Yaris, C-HR, Rav4, etc, the topic will be moved to that specific model club.

[BhxTrev]

Regarding the Prius it's going to behave much the same as the Auris Hybrid since the engines & batteries are more or less identical. I don't have a problem with the issue you raise & if I'm in stop & go traffic, sure the engine will kick in if the Battery gets low but that's to be expected. I'm totally pleased with both the performance & fuel efficiency of my Gen 4 Prius but if you have this problem then you need to consider either a full electric or electric plug in vehicle. Don't think the non plug in Prius sounds to be the car for you. 

[danowat]

You just have to be a bit savvy when driving if traffic, as you say, the last thing to want to do is have the ICE turn on to charge the hybrid Battery when you are stationary (0mpg), so managing it in traffic is just a bit more of a task than I expect Toyota wanted it to be.

It is possible, for the most, to drive around this limitation, but yeah, it's not ideal.

[PeteB]

10 hours ago, FROSTYBALLS said:

At one time this particular club was for the Prius and hybrids. However, with the hybrid drivetrain being extended to the Auris, Yaris, Rav4, etc - not to mention grey imports - , it became difficult to manage with some members posting queries within the specific model clubs, some posting in the Prius/hybrid club, and so on.

When the club format was revamped the Prius/hybrid club reverted to being for the Prius, with other hybrids being dealt with in the specific model clubs. 

In future, if a topic is for the hybrid version of either the Auris, Yaris, C-HR, Rav4, etc, the topic will be moved to that specific model club.

Just an observation, not criticism - there is unlikely to be a perfect solution for this managing which groups to post in.  It's a shame there isn't a way of having a thread display in more than one group.

In this case, if it was posted in an Auris Hybrid specific group, I and perhaps many others on this group would not see it, yet since the Prius has been around for so much longer than other Hybrids, there will be a wealth of experience here that may not be as complete in the other groups.  I, for one, have clocked over 300,000 miles in Hybrids since 2002, 99% in the four generations of Prius, but a little in Yaris, Auris, Prius Plug-In, C-HR, and Lexus LS/RX/NX Hybrids, plus Honda Civic and Insight Hybrids.

[FROSTYBALLS]

7 minutes ago, PeteB said:

Just an observation, not criticism - there is unlikely to be a perfect solution for this managing which groups to post in.  It's a shame there isn't a way of having a thread display in more than one group.

The only way currently for a topic to be displayed in two forums is where a Moderator moves a topic, usually to the most appropriate club, and leaves a temporary link (30 days duration) to the topic, where it was originally displayed. This way any replies to the topic are all kept under the one topic. Where topics are moved from one club to another, temporary links are usually left to direct the OP and other members to the new 'home'.

The previous situation was actually quite messy for members - confusion for some as to which club to post in, topics and replies spread over two clubs, etc.

 

[PeteB]

In my experience, when hitting a big traffic holdup after some miles of steady driving, the HV Battery gauge will most likely be on 6 bars (3 out of 4 on a Gen 1 Prius).  This normally gives about 20 minutes of electric crawling before the engine fires up to charge the Battery (at 2 bars), unless it's very hot or very cold (by UK standards) outside.  Typically, a few minutes of engine will take it back up to 3 bars, and will then stay of for 5 minutes or more (less if you're using lots of electrical accessories like heated seats, heated rear window, fan etc.).

The Gen 4 Prius seems to run the engine a little more aggressively than previous generations (as far as I know only the C-HR using the same fourth Gen Hybrid platform as the Gen 4 Prius) but personally I find this no problem in any generation.  Even in heavy traffic, then only thing I'd rather be in would be a PHEV or EV, but I've found none that meet my requirements as much as a Gen 4 Prius.

[16_Auris_HSD]

Thanks for all the responses.

I'm rarely able to get the charge beyond 6 bars (and only when on a longer run at NSL speeds) and even 6 bars requires fairly light traffic or a steep decline. As it happens living in London the traffic never flows freely and I usually end up bouncing between 2 and 5 bars with 3/4 being typical and 5/6 being "if I'm lucky". 3/4 isn't that much in real life. That's why I'm disappointed. 

It would have been great if Toyota made a two stage regen, one - aggressive for stop and go traffic and the other as it is now for better coasting. I think this is its biggest problem. And perhaps stop the engine from kicking in so aggressively, rather use it to move the car and the Battery to provide the starting kick when moving off (so in other words when the charge is low behave more like a typical ICE with stop and go).

Originally I was thinking of getting the RAV4 HSD. As much as I liked that car I'm glad I didn't get it since the Battery is only marginally larger and it doesn't offset the weight increase.

Just to be clear I do like it when the charge is high enough and am outside of London (even when in traffic). But I always thought these cars were designed to shine in places like London where traffic is permanently bad.

[danowat]

15 minutes ago, 16_Auris_HSD said:

It would have been great if Toyota made a two stage regen, one - aggressive for stop and go traffic and the other as it is now for better coasting. I think this is its biggest problem. And perhaps stop the engine from kicking in so aggressively, rather use it to move the car and the battery to provide the starting kick when moving off (so in other words when the charge is low behave more like a typical ICE with stop and go).

Does 'B' mode do that?

[PeteB]

22 minutes ago, danowat said:

Does 'B' mode do that?

No.  B mode actually saves less electricity, not more.  It's there for two main reasons:

1. to give extra engine braking to aid controlling the car when descending long and/or steep hills
2. to reduce the manual braking effort on a long descent after the Battery has maxed out, when the is no longer any regeneration and the friction brakes do all the work until there's some space in the Battery again.

When you select B mode it makes the ICE turn without fuel to create extra drag from the compression to help slow  the car down (or prevent speed from increasing).

Oh yes, and I've found that in slippery ice/snow it can help to control the car with less sliding than brakes alone, but not everyone agrees with this practice.

[16_Auris_HSD]

Edited: see a more thorough response by PeteB above.

Plug-in Toyota hybrids use B to aid regen apparently.

[danowat]

7 minutes ago, 16_Auris_HSD said:

Edited: see a more thorough response by PeteB above.

Plug-in Toyota hybrids use B to aid regen apparently.

Yeah, probably something to do with the amount of wattage the non-plugin's HSD can make.

[PeteB]

24 minutes ago, 16_Auris_HSD said:

I'm rarely able to get the charge beyond 6 bars (and only when on a longer run at NSL speeds) and even 6 bars requires fairly light traffic or a steep decline. As it happens living in London the traffic never flows freely and I usually end up bouncing between 2 and 5 bars with 3/4 being typical and 5/6 being "if I'm lucky". 3/4 isn't that much in real life. That's why I'm disappointed. 

It would have been great if Toyota made a two stage regen, one - aggressive for stop and go traffic and the other as it is now for better coasting. I think this is its biggest problem. And perhaps stop the engine from kicking in so aggressively, rather use it to move the car and the battery to provide the starting kick when moving off (so in other words when the charge is low behave more like a typical ICE with stop and go).

Originally I was thinking of getting the RAV4 HSD. As much as I liked that car I'm glad I didn't get it since the battery is only marginally larger and it doesn't offset the weight increase.

Just to be clear I do like it when the charge is high enough and am outside of London (even when in traffic). But I always thought these cars were designed to shine in places like London where traffic is permanently bad.

Yes, London obviously challenges the system more, but it does that to any propulsion type and even EVs suffer a range penalty there.

Your experience with the HV Battery gauge pretty much matches my experience there too.  After 30 years in IT, I became a London minicab driver in 2006 for a year using a Gen 2 Prius, but personally, I loved the driving experience (did 46,000 miles in the year!).  From the sound of things, you'd have liked the Gen 2 Hybrid system even less, because when it got to 2 bars, pulling away, especially on a gentle uphill incline, used quite a lot of revs, but it wasn't that loud.  There was no other car at any price available at the time that would have tempted me to make the career change.

I'd like something like the 'mountain mode' in the Chevrolet Volt (AKA Vauxhall Ampera), where at the press of a button the system will try to add charge to the Battery continuously so that it you know you're heading for a long, steep hill climb or traffic jam, you can prepare for it.

I agree the RAV4 HSD is likely to be worse in those conditions.  Also, as it has a 2½ litre petrol engine Vs the Auris 1.8.  I drove a Lexus NX Hyrbid last year which has the same chassis and Hybrid system as the RAV4, and with the addition of poorer aerodynamics to the weight and larger engine, I was surprised how poor the fuel consumption was.

[16_Auris_HSD]

Yeah the refinement is pretty good I must say. The last time I had a car that was so quiet around London was my W211.5 Merc E500. The only time I knew the engine was running was when I had to put another full tank of petrol into it every 200-300 miles (if I was lucky).

I wonder, does anyone know a way to extend the useable Battery range from typical 40-80% to e.g. 20-90%? Something that could be easily reverted back to stock in order not to upset Toyota if it goes in for service?

[PeteB]

2 minutes ago, 16_Auris_HSD said:

...does anyone know a way to extend the useable battery range from typical 40-80% to e.g. 20-90%?...

I wouldn't recommend trying anything like that.

Many were worried when the Hybrids first appeared that Battery life would be a major (and very expensive) problem, knowing how rapidly camcorder, phone and pocket computer batteries of the day died.

It was the careful control of max and min charge, temperatures (HV Battery has its own cooling system) and in/out energy flow rates that proved the secret to making the Battery life better than most people (including myself) thought possible.

BTW, in case you're not aware, the gauge shows a subset of State of Charge - if it ever showed empty on the gauge, there's really about 40% SoC, and when it maxes out (some time after it first goes to 8 bars when descending a long/steep hill), it's about 80% in reality.

If the HV battery gets below 1 bar, the car can't reverse until the charge increases.  This is to prevent the battery becoming dangerously discharged.  Reversing when the engine is running takes extra electricity because the electric propulsion and petrol engine work against each other so the electric motor has to push against the weight of the car and the petrol engine.  And if the gauge is that low, the engine will be running quite aggressively trying to restore the charge to a safe level for battery life.

[danowat]

1 minute ago, PeteB said:

If the HV battery gets below 1 bar, the car can't reverse until the charge increases.  This is to prevent the battery becoming dangerously discharged.  Reversing when the engine is running takes extra electricity because the electric propulsion and petrol engine work against each other so the electric motor has to push against the weight of the car and the petrol engine.  And if the gauge is that low, the engine will be running quite aggressively trying to restore the charge to a safe level for battery life.

Ahhh, now that is interesting (and obvious now I think about it)!, I always wondered why my Battery gauge took a bigger hit than normal when reversing.

[PeteB]

1 minute ago, danowat said:

... I always wondered why my battery gauge took a bigger hit than normal when reversing.

Yes.  The only time I saw 25% on my first Gen 1 Prius (the Gen 1 only had 4 bars for 25/50/75/100% and usually showed either 50 or 75%), was after a very long reverse on a narrow track where there was nowhere to turn round at the end.  Just as I made it back to a proper road, the change became too low to continue to reverse.

[16_Auris_HSD]

13 minutes ago, PeteB said:

I wouldn't recommend trying anything like that.

Many were worried when the Hybrids first appeared that battery life would be a major (and very expensive) problem, knowing how rapidly camcorder, phone and pocket computer batteries of the day died.

It was the careful control of max and min charge, temperatures (HV battery has its own cooling system) and in/out energy flow rates that proved the secret to making the battery life better than most people (including myself) thought possible.

BTW, in case you're not aware, the gauge shows a subset of State of Charge - if it ever showed empty on the gauge, there's really about 40% SoC, and when it maxes out (some time after it first goes to 8 bars when descending a long/steep hill), it's about 80% in reality.

If the HV battery gets below 1 bar, the car can't reverse until the charge increases.  This is to prevent the battery becoming dangerously discharged.  Reversing when the engine is running takes extra electricity because the electric propulsion and petrol engine work against each other so the electric motor has to push against the weight of the car and the petrol engine.  And if the gauge is that low, the engine will be running quite aggressively trying to restore the charge to a safe level for battery life.

Some interesting points there Pete. Especially the reverse situation. This just shows how tricky it must have been for Toyota to get all pieces to work with each other perfectly.

[Cyker]

The thing with the HSDs is they are not inherently that efficient - The only reason they can get better mpgs than a straight petrol is because they can recover a some of the huge amount of energy that would be wasted as heat when braking.

If you can tweak your driving style to maximise that recovery - specifically braking earlier, gentler, and for longer, then that will boost the amount of energy recovered.

 

If I drove one the way I drive my D4D (I tend to brake harder over shorter distances) I've no doubt I'd get pretty abysmal mpgs.

In start-stop traffic, the best thing to do is try and conserve as much momentum as you can; Don't stick on the **** of the car in front - Accelerate slightly slower so a bit of a gap builds then when they stop you can gently brake for longer instead of immediately stopping too. If you get good enough, you can continually coast with only light braking and accelerating without ever having to stop, or at least stopping less.

One of the reasons I get such high mpgs in my D4D is because while everyone around me is accelerating a short distance then braking over and over, I'll just be rolling on idle letting the gap in front of me grow and shrink without having to stop.

You do have to beware of dickheads cutting in, but I find most drivers stick to their lane even when a lane is seemingly empty (One of the reasons I tend to stick in the 'slow' lane - It's often the fastest lane when there's congestion!)

re. the max charge, the Battery charge supposedly won't max out; IIRC someone on here posted that the last two blocks are normally kept free and the only way they'd ever gotten them to charge was on a long hill descent in B mode.

 

[PeteB]

1 hour ago, Cyker said:

... re. the max charge, the battery charge supposedly won't max out; IIRC someone on here posted that the last two blocks are normally kept free and the only way they'd ever gotten them to charge was on a long hill descent in B mode.

It's certainly very rare, but it seems, less rare the newer the Hybrid Generation.

Firstly, "maxed out" doesn't just mean all the bars are lit - it takes quite a lot of extra regeneration after the eighth bar lights up before the system truly maxes out.  The car's behaviour changes when this happens, and you're likely to be very aware of it because the sound changes, but mostly the braking changes.  It's still well power assisted, so won't be too onerous, but B mode certainly seems to make it a bit less of a chore.

I'd covered getting on for 100,000 miles in 4 years in my first Prius Gen 1s before I experienced this, but a holiday in Scotland made it a daily occurrence.  When reaching the bottom of a 5-6 mile 20% (1 in 5) hill, you got a good idea what an EV would feel like as the Hybrid System tried like made to use up some of the excess electricity so there'd be room for more free energy when braking or going down the next hill.  The Gen 1 had no EV button, but while maxed out modest pressure on the accelerator would see electric only driving up to at least 60 mph!

 I never experienced a single max out in a Gen 2.  I never owned one, but did about 50,000 miles in cars owned by my firm.  This was mostly in or around London, so no hills big enough to manage 8 bars lit, never mind maxed out.

I owned a Gen 3 Prius for 4 years (60,000 miles) before my current Gen 4 and only got maxed out a few times during a break in Devon last year.  I did' however, notice it was easier to get 7 bars lit in normal driving using my normal careful economic braking that Cyker described than in previous generations.

I've had my Gen 4 since June last year and covered 21,500 miles so far.  Again, not a single max out.  It seems even easier than the Gen 3 to light 7 bars, and on very rare occasions 8 bars (but nowhere near maxed) particularly on a series of roundabouts with 70 mph limits in between.

[barrycoll]

Like Moo, I too find that letting the car idle forward brings its rewards.

Using anything other than basic throttle in EV mode doesn’t really make much more progress, but does suck up the Battery

However if the traffic is Mway stop & go,  I tend to let a gap build up and then use sufficient right foot to just bring the ICE in, and then completely OFF the accelerator to bring the EV light on again for the drift up to the next bunch of stop lights, possibly collecting an Battery bar as well.

   On last weeks trip up to Norwich, i tried to use this Pulse and Glide as much as poss even on the Mway, but not just feathering he throttle but taking the foot right off for a millisecond to engage the EV light, and then just enough throttle to keep the EV light without loosing too much momentum......this is not supposed to work for the Gen 4, but using the slight uphills and descents this way raised the mpg from mid 50s to low 70s quite quickly.

 Possibly a lot easier to use radar cruise, but more fun to keep the brain engaged too, and for me, heavy trafficis is an opportunity to sensibly use the ICE to stop using up those hard purchased Battery bars.....seems counter-intuitive but does also seem to work.

[16_Auris_HSD]

The letting the gap build up business is somewhat controversial.

It could be viewed as fairly OK in stop and go traffic on a motorway (where there are no side roads and junctions) - depending on how many car lengths we're treating as acceptable. Some like to get up to 20 car lengths before pushing and gliding, which is selfish.

In a packed city like London it is almost unacceptable, in my opinion. The number of cars combined with limited space, traffic lights every X00 yards and traffic trying to join from side roads or cross demand military like synchronisation otherwise we'd never get anywhere and any individual saving would be offset by macro loss caused by the increase in time needed to move from one place to another. I'm not advocating tailgating obviously but 2 to 3 car lengths is optimal for traffic flow.

[Sooty]

A lot of people tend to forget that the HSD is a "Battery assisted petrol engine system" and not a "petrol engine assisted Battery system".

[johalareewi]

Back from hols.  To chip in with a couple of notes:

B Mode on the non-plugin hybrids does not boost Battery charging (despite what MrT sales staff say) it turns on engine braking to waste energy.

B mode on a plug in prius does boost Battery charging but only when in EV mode.  When in HV mode B mode behaves as above.

If you are stuck in traffic and want to charge the HV Battery right up, you can apply the main brakes using your LEFT foot and put the car in D.  With your LEFT foot still on the brake pedal, press the accelerator with your right foot.  The ICE will fire up and charge the HV battery.  However, this is probably less efficient than letting the HSD do what it needs to.

 

[Anthony Poli]

One thing you could try using, is the hybrid assistant. Recently I have seen the optimum points in power dial give the most ice recharge and the amount of regen gained from different amounts of pressure on the brake pedal.

Also it shows how much power the electric motor is using.
With this new information, I have managed to do my commute and between 47 & 63 % of my journey can be done without fuel. Stop starts going up a steep hill will drain the Battery without you trying.


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