Latest Hybrid STILL not better than Diesels???

[Whitton Race]

Many thanks, that is what I will do.

[YarisHybrid2016]

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Do not underestimate the importance of audio cues to the brain.

Definitely not! I still have problems maintaining speed due to the fact I can't "hear" the speed, even though I'm much more "in tune" with it now than when I first got it (I say that as if I'm bad at holding speed - generally I'm not, but I have to glance so much more often at the speedo to compensate). I have got much better at reading the road and knowing how much to adjust the power by to maintain speed as I go up/down hill, even on slight inclines.

One thing I do is pretend I'm flying an aircraft - there too the engine RPM is completely disconnected from airspeed, and that analogy helped me to adapt pretty quickly.

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I don't think it is that noisy

Me neither! Even when it is at its "noisiest", IMHO it is still quiet! Road noise is by far the loudest thing generally. I can comfortably hear the whine of the electric motors under acceleration/braking so that really speaks to how quiet it is. Once it is most of the way out of the power band, the engine just disappears.   Actually, something I wondered is whether entering the power band changes the timing of the engine and hence why it is noisier? Try gently entering the power band and listen to the engine sound. A similar thing happens during warm-up when it is idling. There is a change in sound.

One thing I'd love to know is why does the car have so much performance during warm-up where it is apparently holding the engine at idle and using electric power only? This is witnessed by lack of engine sound/increase in RPM during modest acceleration and very low fuel consumption (70+ instantaneous). Once it exits this mode of operation, the engine note changes and the engine is more active. I'm curious as to why this mode isn't available during normal driving at low speed, as it seems to force-exit under hard acceleration/speed > 30 MPH). I'd be happy to trade performance for economy, in a "super economy mode" for example for town driving.

If it is in this mode at low speed, you can feel it exiting by what I call the "hybrid bump", where the engine is apparently taking some of the driving load (the bump), and the fuel consumption increases (from 70+ instantaneous, to ~35 MPG at the same speed).

I've also found that if holding speed at 40 MPH and the HV Battery is charging, when the system gets close to running in pure EV mode, first the fuel consumption drops, then just before it transitions to EV only mode, there is a slight burst in performance requiring a slight lift-off the throttle to compensate, followed by the engine stopping and EV mode becoming active. It's just fascinating!

[Joseph D]

On 09/05/2017 at 1:34 AM, YarisHybrid2016 said:

A similar thing happens during warm-up when it is idling. There is a change in sound.

Yes, that is correct. The initial start up has the engine and valve timing set so the engine warms up quicker. At 40-45 sec into the 55 sec stage 1 warm up, you can hear the valve timing reset.  In this stage 1 configuration the engine is not very efficient or powerful so the electric motor provides the bulk of the power.

On 09/05/2017 at 1:34 AM, YarisHybrid2016 said:

One thing I'd love to know is why does the car have so much performance during warm-up where it is apparently holding the engine at idle and using electric power only?

Because it is using the electric motor primarily and electric motors have great torque which compliment the ICE.

On 09/05/2017 at 1:34 AM, YarisHybrid2016 said:

I'm curious as to why this mode isn't available during normal driving at low speed, as it seems to force-exit under hard acceleration/speed > 30 MPH (48.28km/h)). I'd be happy to trade performance for economy, in a "super economy mode" for example for town driving.

Yes it does force to stage 2 if you request power by pushing down more on the go pedal.  It is not available in general because it is actually very demanding on the Battery.  When the Battery is new and in good condition it is not really a problem, but as the Battery ages it can take longer for the battery to recover from the heavy demand.  As for more economical, it isn't.  Any energy drained from the battery must be replaced and ultimately that comes from using fossil fuel to run the ICE.  But what about regen, I hear you say? The momentum the car has is still ultimately provided by burning fossil fuel.  The trick to real economy in these hybrids, is how to juggle the inputs judiciously to make the best outputs in the form of high MPG readings. Going out of your way to run on electric only, is not one of them.  The real trick is to ensure you run the ICE more (if circumstances permit-sometimes you just have to run on electric), but at an economy rate 10-15 mpg (or more) above the desired average rate.  That way if you need to accelerate or climb an incline, you have reserve in the battery to run your electric motors.

If you look at your model and model year on Fuelly.com, you will see how varied is peoples success in regards of average fuel consumption per vehicle.  It may or may not make one feel better about one's own efforts.

[YarisHybrid2016]

Thanks for the explanation.

Stage 1 - I was referring to the instantaneous MPG. It's a curious thing - when the car has been sat overnight with let's say 50% SoC, then it is driven, fuel economy is a fairly steady 35 MPG or so until it is warmed up. Sometimes though, it will be a fairly steady 70 MPG, which is similar to the situation of driving steadily at 40 MPH just before the car auto-enters EV mode.

I didn't realize it relied so much on the Battery during this phase. I thought perhaps the engine was idling enough to sustain the electric motor under modest acceleration (with some Battery usage), and it exited stage 1 under heavy acceleration as the ICE is *required*.

I have certainly found it beneficial to run the ICE, particularly during acceleration.

I modified my driving slightly so I use more of the Battery during initial acceleration, then triggering the ICE later to get to speed, based on a few comments here. It seems to have made a good difference (before, I was using the ICE to accelerate, gently, to speed, and the battery to sustain speed in EV mode at 30/40 MPH).

[Joseph D]

25 minutes ago, YarisHybrid2016 said:

I modified my driving slightly so I use more of the battery during initial acceleration, then triggering the ICE later to get to speed, based on a few comments here. It seems to have made a good difference (before, I was using the ICE to accelerate, gently, to speed, and the battery to sustain speed in EV mode at 30/40 MPH (64.37km/h)).

While that is a change in the right direction, I wouldn't overly favour the electric.  I agree with ditching the gentle acceleration.  However, I would favour an initial "more than gentle but less than aggressive" approach.  My "feel" is an initial punch to 3/4 of the go pedal (if circumstances permit) and then feather it as I get to 2/3 of the target speed. You will notice that as you feather the go pedal and the MPG's start climbing, you can maintain the same acceleration. I then pull (reasonably) abruptly right back on the go pedal as I hit my target speed. Sorry for the general language, but I'm not sure if I gave you the numbers I go by whether they would apply to the Yaris.

Anyway, keep up the good work.  As your history of improvement shows, some of the technique is naturally assimilated.

[YarisHybrid2016]

(There are too many factors hence why I'm considering making a video for people new to hybrids).

I completely agree! I discovered this some time ago, that it is better to get it rolling then ease off, than to gently set off (integration is annoying!).

In the Yaris, I found the car is pretty lively to around 40 MPH, so just pulsing the throttle so it maybe even gets into the first 1/4 of the powerband is OK, if you then lift off as the car accelerates through 30 MPH, back to the tick mark 1 below the powerband passing 40 MPH (if going for 60-70 MPH) or two tick marks (if going for 50 MPH).

I also reference instantaneous MPG as this helps with not being too heavy-footed.

I've also found I do much of this now without thinking too much about it - I'll glance the power needle dropping out the corner of my eye as I unconsciously lift off.

Up to 20 MPH I've found I can give it a decent amount of power without hurting economy too much. It's generally better to keep the car rolling at 15-20 MPH or even a bit faster approaching roundabouts, as much fuel is used in just getting going again.

[Joseph D]

Pretty much in agreement with all of that.

[johalareewi]

" Any energy drained from the Battery must be replaced and ultimately that comes from using fossil fuel to run the ICE"

The energy drained from the Battery doesn't HAVE to be replaced.

The only time the HV Battery HAS to be charged is when the charge level goes below the lower limit.  The ICE will fire up and will charge the HV battery until it is above the lower limit.  Any other charge above this is a bonus which has been scavenged either by regen braking, or surplus from the hybrid system.  True it came from the ICE originally (= fossil fuel) but this fuel wasn't burnt specifically to charge the HV battery.

 

[Joseph D]

42 minutes ago, johalareewi said:

The energy drained from the battery doesn't HAVE to be replaced.

The only time the HV battery HAS to be charged is when the charge level goes below the lower limit.  The ICE will fire up and will charge the HV battery until it is above the lower limit.

This is a sematic and totally irrelevant argument. Furthermore whether it HAS to be replaced or not, the HSD system WILL replace the energy as it likes to keep the Battery at 60% SoC.  Whether it does it immediately or at a delayed point doesn't change the fact it does it.

42 minutes ago, johalareewi said:

Any other charge above this is a bonus which has been scavenged either by regen braking, or surplus from the hybrid system.  True it came from the ICE originally (= fossil fuel)

It is maybe a bonus, but it is precisely the way in which the HSD is able to be more efficient -- harnessing energy that would otherwise be wasted -- compared to regular fossil fuel vehicles. So isn't that the essence of what I said.  I reiterate, the momentum the car has (which is used by regen) is still ultimately provided by burning fossil fuel.

42 minutes ago, johalareewi said:

but this fuel wasn't burnt specifically to charge the HV battery.

Please do not put words in my mouth, I never said that fuel had to be specifically burnt to charge the HV Battery. Further, this was not really the point of what I was saying, and is largely irrelevant.

In the end, the ICE is the only source of energy, so all energy must come from it. There is no perpetual motion device hidden in the HSD. Anybody with a rudimentary grasp of physics knows that energy is not created, merely transformed from one form to another.

[Whitton Race]

Diesels are quite poor for fuel economy in built up areas.  The modern ones with stop-start helps, but still you sit in traffic and just see the mpg figure fall rapidly.

I have never understood whey there is not a diesel hybrid - that would seem to give the best of both worlds, or am I missing something there?

[PeteB]

20 minutes ago, Whitton Race said:

... I have never understood whey there is not a diesel hybrid - that would seem to give the best of both worlds, or am I missing something there?

The torque patterns of electric motor and petrol complement each other to a greater degree than electric and diesel.  Diesel enginess also tend to be more expensive to make, so the benefits aren't as great for a diesel hybrid.

Development might change that in the future.

There are a few, three come to mind:

• Citroën DS5 DSign Hybrid
• Peugeot 3008 Hybrid
• Volvo Hybrid

 

[FROSTYBALLS]

PSA are killing off their diesel hybrids in favour of petrol hybrids - due to be completed around 2019.

[Anthony Poli]

2 hours ago, PeteB said:

The torque patterns of electric motor and petrol complement each other to a greater degree than electric and diesel.  Diesel enginess also tend to be more expensive to make, so the benefits aren't as great for a diesel hybrid.

Development might change that in the future.

There are a few, three come to mind:

• Citroën DS5 DSign Hybrid
• Peugeot 3008 Hybrid
• Volvo Hybrid

 

I would have thought there was a weight difference too, added complexity with the particulate filter, as short runs aren't suited.

 

[Whitton Race]

Perhaps what is needed is a plug-in diesel hybrid, so any town journeys are solely hybrid and motorway is solely diesel...

[myriagon]

I would be surprised to see many more diesel cars nevermind diesel hybrids or plug-in diesel hybrids. The poor air quality in cities caused by diesel pollution and the rapid introduction of clean electric vehicles will see to the end of diesel cars. If the rumours in the press are to be believed, the government are considering a scrappage scheme for older diesels.

In an attempt to meet ever more aggressive emission targets, diesels have become overly complex and expensive to maintain. A diesel hybrid would be even more complex than a diesel. Even with all the complexity, the VW scandal has shown that diesels are not as clean as they should been and goes some way to explain why air quality in cities has not improved as expected. Of course in the case of London, diesel black cabs and old buses have played a major role in the pollution too.

Personally I think even petrol hybrids like the Prius will struggle to survive in the medium to long term in the wake of electric vehicles.

[Whitton Race]

Hmm, yes I would quite like an electric car but they are expensive and range limited.  Both of those will be addressed to some extent going forwards, but the big challenge I see with electric cars whatever they do with the Battery is that the Battery will always have a range (as does a petrol / diesel fuel tank) but when that range is expired, charging is going to take some time unlike current refuelling at a petrol station.  There will always be the longer journey people need to make, whether regular or just the family holiday.  With a petrol / diesel it is possible to drive, say, London to Snowdonia and refuelling is easy to include in the stop but with an electric car once you are out of range it seems to me you would always need an over-night stop.  That is the biggest catch and would need to be resolved before electric cars can become the drivers only car.  I am sure it will be resolved and the government will find a way to tax electric cars too then.

[myriagon]

Even now Tesla claim they can recharge for up to a 170 mile range in as little as 30 minutes. I expect that time will come down in the future. See https://www.tesla.com/charging 

Having driven 170 miles, or more if using an overnight charge, then a 30 minute or longer break seems sensible.

[PeteB]

3 hours ago, myriagon said:

Even now Tesla claim they can recharge for up to a 170 mile range in as little as 30 minutes. I expect that time will come down in the future. See https://www.tesla.com/charging 

Having driven 170 miles, or more if using an overnight charge, then a 30 minute or longer break seems sensible.

It does in the USA where there are thousands of Tesla (free for life) very fast SuperCharger stations.  When I looked at a Model S for me here in Norfolk, there were only about 25 in the UK, and none east of the A1.  I believe there is now one at Elveden, near the A11, but that would rarely help me out.  Such a large Battery would take about 30 hours to recharge if all I could find was a domestic socket, so a day trip to Hull would be challenging!  Using the web searches, I found almost no suitable EV charging stations on my route.  And even the fastest non-Tesla charger would take a few hours to give me enough to get back home.

A £,4000 upgrade would have bought a version with a bigger Battery, that was claimed to be good for up to 300 miles, but that was only if you accelerated very gently, did 55 mph or less, kept the windows shut, the A/C and heater off.  Realistically, 220 miles was more likely.

It would be plenty for me for about 90% of the days I drive, but a right royal pain the rest of the time.  Had there been the level of SuperCharger coverage the US has, I might have bought one, until I discovered no rear wiper (even on the Model X SUV) and no head up display.

[Cyker]

20 hours ago, Whitton Race said:

Diesels are quite poor for fuel economy in built up areas.  The modern ones with stop-start helps, but still you sit in traffic and just see the mpg figure fall rapidly.

I have never understood whey there is not a diesel hybrid - that would seem to give the best of both worlds, or am I missing something there?

That's actually not true; I mean yeah, the fuel economy is worse in built up areas, but it's still better than straight petrol! Diesels are not great in built up areas because they don't get loaded enough to run at their best efficiency, but an idling diesel engine wastes *far less* fuel than an idling petrol engine, which is wasting energy fighting against the closed throttle when idling.

Diesels also have the advantage that they can run at much lower RPMs - In slow crawling traffic I'm often letting it crawl along idling in 4th gear at 18-20mph or 3rd at 12-13mph which it is happy to do; When I tried that in my courtesy Aygo and it stalled almost immediately!  (That 3-pot reaaaally doesn't like low RPMs)

 

I'm always hearing petrol engines revving up to move off when I'm in traffic, but you don't need to do that in a diesel.

 

 

But yeah, being stuck waiting is not great in a diesel as they like to be run hot to be efficient and you can't get a diesel engine hot while idling. Petrols can because they waste so much heat energy.

 

This is also why they aren't great in hybrid systems - If you put a diesel engine in a HSD it would never reach optimal operating temperature (Well, maybe it would if Ken Block or Jeremy Clarkson was driving it ) and you'd probably burn out the poor MG1 from constantly start-stopping that heavy lump!

 

The only place I can see it working would be in a truck as petrol is never going to replace diesel in the haulage industry, or anything that deals with really heavy things - It's limited compression ratio means it just doesn't have the torque to move heavy loads without burning a lot more fuel. The combination of a leccy motor to conserve braking energy and use it to move off again would save a lot of fuel and wear and tear, but unless the Battery was absolutely huge it wouldn't be able to sustain that over the course of the average trucker's run!

But for cars, electric is the way of the future! We just need a breakthrough or alternative to batteries... I mean c'mon, we're 2 years past 2015 - Where's my Mr Fusion??? 

 

[mysecondavensis]

5 minutes ago, Cyker said:

But for cars, electric is the way of the future! We just need a breakthrough or alternative to batteries... I mean c'mon, we're 2 years past 2015 - Where's my Mr Fusion??? 

 

Mr T has the Hydrogen Fuel Cell/electric in operation .

Interesting points BTW Cyker

[Anthony Poli]

But not many places to fill up yet.

;-)

 

 

Sent from my iPad using Tapatalk

[Cyker]

I must admit I'm not a big fan of hydrogen - The amount of energy you waste to extract it is ridiculous; You'd be better off using the energy on James May's solar furnace to turn CO2 into more petrol and diesel!

Also, large concentrations of free hydrogen scare the **** out of me - It will leak through almost anything, causes metal to become brittle and crack over time and it will happily combine with any free oxygen with very little persuasion, and do it very very quickly. As in kaboom!

 

That said, I know these concerns are rather ironic considering I was just asking why I don't have a mini nuke reactor to power my car yet 

The former issues could go away if we can get into Space! and e.g. go mine Jupiter and Saturn for hydrogen fuel (I used to do that in Frontier: Elite 2 so it must be possible! ), or someone comes up with a catalyst. The latter we can engineer around; The hydrogen tanks in the Mirai are so wonderfully over-engineered that I feel content that at least Toyota are serious and aware of what a ***** hydrogen is to deal with!

 

 

I must admit I was hoping for someone to come up with some kind of super duper quantum stealth turbo mach 7 capacitor Battery... (That's a joke for any Dara O'Briain fans )
 

[FROSTYBALLS]

Toyota have been quietly testing a hydrogen fuel cell truck for a couple of years:-

https://arstechnica.co.uk/cars/2017/04/toyota-hydrogen-fuel-cell-trucks/

https://www.forbes.com/sites/alanohnsman/2017/04/19/toyota-rolls-out-hydrogen-semi-ahead-of-teslas-electric-truck/#2ed71c2b582b

http://www.autoblog.com/2017/04/23/toyota-project-portal-hydrogen-semi-drag-race-video/

 

[YarisHybrid2016]

On 5/12/2017 at 6:43 PM, Anthony Poli said:

But not many places to fill up yet.

;-)

 

 

Sent from my iPad using Tapatalk

I keep a box of plutonium on the back seat... 

I like the Mirai, but if it is to be a success they need to seriously work on fuelling stations for it. Could we even realistically produce that much hydrogen just for it to sit around fuelling stations?

[Anthony Poli]

I bet you will still see people filling up while smoking