Yaris Hybrid Fuel Economy

[Mike J.]

On 09/08/2017 at 4:39 PM, CPN said:

On the Yaris, if you watch the gauges in an app like Hybrid Assistant (which I now use regularly) or even Torque (which I still have but don't use as much) you will see that even in aggressive braking, the mechanical brakes come in far earlier than maybe they should and only ever regenerate a maximum of about 20ish Amps back charging into the HV battery.

Nope, I have just checked Hybrid Assistant on my Yaris Hybrid and with firm, but not aggressive braking, I saw 90A flowing into the Battery! I suggest that 100A may be the limit.

The reason the new Prius is better is that it is more streamlined, the Battery is bigger and 'better' and the petrol engine is more efficient. I think that the max. 'EV only' speed is over 60mph, so this would also help.

One interesting item is that our electric motor has more torque - 169 versus 163Nm. Power is 8kW lower. The Prius petrol engine is around 25% more powerful.

[Anthony Poli]

I’m away this weekend so I will be doing about 400+ miles in the Auris. So I will be able to compare both cars when driven on the motorway at 70. Already have the Yaris data.

 

 

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[Anthony Poli]

I had noticed this, but thought it was an error, as it didn't seem to match the Yaris display - I am not convinced that the Yaris software suddenly changes the regen display info depending on whether it is brake or cruise control derived.

After extensive testing and experience with Torque, Techstream software and latterly, Hybrid Assistant, I am more inclined to believe the PIDs coming directly via bluetooth from the ECU to my phone monitor than a rather vague meter on the dashboard which doesn't "tell you" very much frankly... 

 

 

The dashboard information is usually wrong or lags, the dashboard has should 100mpg and the obd shows fuel being used, albeit not a lot.

 

 

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[Mike J.]

On 11/08/2017 at 1:30 PM, Mike J. said:

I have just checked Hybrid Assistant on my Yaris Hybrid and with firm, but not aggressive braking, I saw 90A flowing into the battery! I suggest that 100A may be the limit.

Digging deeper, I had a look at the log files and found that both during braking and coasting (downhill with cruise on) I got over 17kW peak put into the Battery a few times. With the old P=IV (V=144), that gives about 120A.

[CPN]

You're absolutely correct! I did some checking whilst out and about today and some aggressive braking checks showed similar figures on mine! It seems that I am being too gentle during normal driving lol!

[Anthony Poli]

Sadly it’s not the peak current, but the length of time that power is generated for. That’s why the display shows 30Wh, and since the Battery is over 800Wh, the sort of return I have seen is 60+Wh max.

 

 

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[Mike J.]

45 minutes ago, Anthony Poli said:

Sadly it’s not the peak current, but the length of time that power is generated for. That’s why the display shows 30Wh, and since the battery is over 800Wh, the sort of return I have seen is 60+Wh max.

30Wh is about 6 seconds of hard braking and seeing the display slot shows 1 minute, it is, in theory, possible to get 10 30Wh items displayed - down a steep mountain road using cruise at 30mph say .

I believe the batteries are 20 6.5Ah 7.2V packs, so the power is 936W. If we had full access to the charge, the Yaris could drive around 5 miles at 30mph on electric, but as only about 20% (as shown by Hybrid Assistant) is available we only get 1 mile. So, as we can only add around 200W, you would only ever see a maximum of 6 30W items in any one minute - another challenge .

[Anthony Poli]

The only big decent I have had the chance to see how the hybrid system does. Last night I came back over M62 ( the highest point ) saddleworth to milnrow. Cruise on 70 and it actually showed no fuel used for about a mile and the needle was on the line between charge and eco for a minute. Which is supposed to be the goal for maximum efficiency.

 

 

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[dcweather]

On 04/06/2017 at 6:10 PM, Anthony Poli said:

The one thing that really messes up your mpg, is constantly varying speed, mainly stopping for traffic lights.

Yes, a bit of a nuisance I know when they are on red but I find it helps avoid accidents :-)

[dcweather]

On 06/07/2017 at 2:37 AM, YarisHybrid2016 said:

 but it would *seem* that if I take the slightly longer route out the village, through 30/40 limits to the main road, I get wildly better fuel economy despite it being up-hill than taking the more direct route at 50 MPH (also slightly up-hill, but very slightly more so). In both cases, it's running the ICE.

Don't forget that mpg can actually be an irrevelent measure if you are actually trying to save money. It is petrol consumed for a given A-B journey that matters. So e.g In your example taking a longer route and warming up to get more mpg would depend on how much longer. e.g. 5 miles at 60 mpg will cost approx 33% more than 3 miles at 50 mpg

[Anthony Poli]

The good thing about this topic, is sharing our experience to see how each method works for some and not others .

 

At the end of the day I’m happy with the miles per tank and if I can better it each time.

 

 

 

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[YarisHybrid2016]

On 8/14/2017 at 1:18 PM, dcweather said:

Don't forget that mpg can actually be an irrevelent measure if you are actually trying to save money. It is petrol consumed for a given A-B journey that matters. So e.g In your example taking a longer route and warming up to get more mpg would depend on how much longer. e.g. 5 miles at 60 mpg will cost approx 33% more than 3 miles at 50 mpg

Yes - I understand this! :)

It was an interesting test as the distance is nearly the same, but the roads quite different. The end result was basically the same.

I haven't been able to do anything to influence the MPG during warm-up (35 vs. 40 MPG maybe) which was the point of the test.

I'd be interested to know if others get similar results (journey needs to be at least 15 minutes in order to ensure the car can exit warm-up). I find it leaves warm-up after approx. 5 minutes, and I start to see significantly higher MPG. It increases gradually, too, not immediately.

Whether the transmission and bearings are warm also have an influence, so it is best to try this on the first journey of the day.

[Anthony Poli]

On 16/08/2017 at 5:53 AM, YarisHybrid2016 said:

On 14/08/2017 at 1:18 PM, dcweather said:

Don't forget that mpg can actually be an irrevelent measure if you are actually trying to save money. It is petrol consumed for a given A-B journey that matters. So e.g In your example taking a longer route and warming up to get more mpg would depend on how much longer. e.g. 5 miles at 60 mpg will cost approx 33% more than 3 miles at 50 mpg

Yes - I understand this! :)

It was an interesting test as the distance is nearly the same, but the roads quite different. The end result was basically the same.

I haven't been able to do anything to influence the MPG during warm-up (35 vs. 40 MPG maybe) which was the point of the test.

I'd be interested to know if others get similar results (journey needs to be at least 15 minutes in order to ensure the car can exit warm-up). I find it leaves warm-up after approx. 5 minutes, and I start to see significantly higher MPG. It increases gradually, too, not immediately.

Whether the transmission and bearings are warm also have an influence, so it is best to try this on the first journey of the day.

I’m curious to drive a normal petrol again, just to see what the instantaneous readings are for my journey to work to compare.

The difference will be when the hybrid is on electric on the flat, the petrol can only do the no fuel usage when slowing down or downhill

 

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[Anthony Poli]

Can anyone tell me for certain, does the car display the 30Wh graphic only show when braking?

 

 

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[dcweather]

On 16/08/2017 at 5:53 AM, YarisHybrid2016 said:

Yes - I understand this! :)

It was an interesting test as the distance is nearly the same, but the roads quite different. The end result was basically the same.

I haven't been able to do anything to influence the MPG during warm-up (35 vs. 40 MPG maybe) which was the point of the test.

I'd be interested to know if others get similar results (journey needs to be at least 15 minutes in order to ensure the car can exit warm-up). I find it leaves warm-up after approx. 5 minutes, and I start to see significantly higher MPG. It increases gradually, too, not immediately.

Whether the transmission and bearings are warm also have an influence, so it is best to try this on the first journey of the day.

Sorry, it did sound a bit patronising but ti's the sort of thing I might go and do! Definitely get more mpg after about a five minute warm up but that seems to apply to our petrol cr as well. As I have said before though, I defy any other non hybrid/electric automatic car to get  52 mpg from cold on a 3 mile urban trip!

[Ricey155]

Good read 👍 

Anyone got a real world idea on standard petrol 1.5 to 1.5 hybrid mpg? 

Test drove a 65 plate 13k on the clock and say around the 50mpg mark. Great comfy drive I'll add 😉

[bob-the-builder22]

I have now completed 5k in the face-lift yaris hybrid. On a mixture of driving mostly at rush hour I have averaged a displayed mpg of 58.5mpg and a calculated mpg of 55.5mpg. I had a 1.0 new polo before the yaris and that returned 45mpg on the same commute, I'd imagine the yaris would get similar. 

[Ricey155]

Early days and its first trip to work and back today 48MPG, need to work out when to use the EV button at some stage for that extra MPG hit.

[Anthony Poli]

Early days and its first trip to work and back today 48MPG, need to work out when to use the EV button at some stage for that extra MPG hit.

 

Forget the EV button, the will run on EV at speeds upto 50mph without it. Just build up your speed to the desired speed and then take your foot off the gas, now just apply just enough pressure to keep the power needle below the C in Eco and the car will stay in EV.

It will also work with cruise control.

 

A light foot will make a lot of difference.

;-)

 

 

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[Mike J.]

3 hours ago, Ricey155 said:

...... need to work out when to use the EV button at some stage for that extra MPG hit.

I only use it 'usefully' when in a queue in town where I can keep up with traffic pulling away from the lights - "EV mode" allows you to power into the upper range of the ECO display, otherwise the petrol engine will cut in. EV mode cannot be used with cruise control and will also cut out at around 28mph (but EV driving can continue up to around 42mph if the power meter stays in the lower part of ECO). When the engine is cold 'EV mode' will cut out at lower speeds and will not be available at low Battery power. Isn't software wonderful.

Here is a useful web page showing you why the EV limit is around 42 mph: Power split device.

[davekench]

I have a 64 Yaris Icon with 23k on the clock only owned this vehicle for 6 weeks and I tried the mpg test from a full tank to brim and refill to brim after a journey, this journey comprised of travelling to and from work 22 miles eachway using a mixture of round, non motorway, and then a round trip to the coast by M23, A23 from near Gatwick and after 374 miles I refilled my tank and managed to get 23.26ltrs in the tank to fill it, that equates to 5.17galllons and gives me 72.533 mpg. I am very happy as my Nissan Note Auto was only doing 42mpg thus saving me around 30mpg!

[YarisHybrid2016]

Winter is here, and I've done several trips of around 25 miles each in temps of around +1 to +3 deg. C, and had the computer report an average of 58-65 MPG.

My driving style is a bit different however - I am accelerating quite a bit slower, driving slightly slower (instead of accelerating to 50 MPH before a corner, to 40 MPH, before slowing to less than normal speeds, to allow for ice), and not braking at all for junctions* (it upsets the drivers behind, but we're all safer for not sliding at 60 MPH out of the junction into traffic!).

*obviously if I need to stop, I do, but I otherwise keep it rolling, but just let the car decelerate rather than braking to decelerate.

I make it sound like I'm driving at a snail's pace; I'm not. I'm just doing everything a bit slower, letting the car decelerate longer without touching the foot brake. My normally 28 minute journey takes 30 minutes. It's extremely consistent (actually, I find it really quite spooky).

I've been running the climate control at 23 deg. C, and so far it doesn't appear to be nearly as detrimental as I thought it might be to fuel economy.

So far, extremely happy! This includes the warm-up/running the heater at the start of the journey (no cheating by resetting the average after the warm-up!). 

[Mike J.]

My 10 mile trip to the station at 6am at 0 deg. C is now only getting me 50mpg 

[Anthony Poli]

Winter is here, and I've done several trips of around 25 miles each in temps of around +1 to +3 deg. C, and had the computer report an average of 58-65 MPG.
My driving style is a bit different however - I am accelerating quite a bit slower, driving slightly slower (instead of accelerating to 50 MPH before a corner, to 40 MPH, before slowing to less than normal speeds, to allow for ice), and not braking at all for junctions* (it upsets the drivers behind, but we're all safer for not sliding at 60 MPH out of the junction into traffic!).
*obviously if I need to stop, I do, but I otherwise keep it rolling, but just let the car decelerate rather than braking to decelerate.
I make it sound like I'm driving at a snail's pace; I'm not. I'm just doing everything a bit slower, letting the car decelerate longer without touching the foot brake. My normally 28 minute journey takes 30 minutes. It's extremely consistent (actually, I find it really quite spooky).
I've been running the climate control at 23 deg. C, and so far it doesn't appear to be nearly as detrimental as I thought it might be to fuel economy.
So far, extremely happy! This includes the warm-up/running the heater at the start of the journey (no cheating by resetting the average after the warm-up!). 

I do the same sort of thing at this time of year, some of things all year round. Why come to a stop, when you know the traffic lights will change as your wheels stop. It might upset the idiots behind me, but why waste fuel when you can keep a constant speed in EV.


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[Anthony Poli]

Managed 58.7 over 14 miles, with varying speed limits. Had the cc set to 22 using auto.


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