Eco Drive Ratio Confusion

[BigKeith1962]

Hi All,

I was wondering if someone can shine some light on the EV ration for me.
I have recently been paying more attention to my fuel usage due to high mileage. I drove the other day around 10 miles though town towards the motorway in EV mode and then around 70 miles on the motorway with the engine running, on a near enough empty motorway.
When I pulled over at the service station I noticed that my EV drive ratio is at 30%.
Has anyone seen this? If so then can you explain how it works as I cannot figure it out.

 

[ChrisMiller]

It doesn't only count your pure EV mileage. Once the battery is exhausted, the car continues in hybrid mode, using the engine to propel the car and also charge the battery (at 70 on a motorway, this will probably be in 'parallel' mode with the engine driving the front wheels directly and also generating electricity to recharge the battery). You might travel (say) 3 miles on petrol and the car (having charged the battery sufficiently) will automatically switch back to electric mode for (say) 1 mile, which would show as a 25% ratio. Add in your initial 20+ miles on battery alone and that will take you to around the 30% figure you've seen. Even if you never charge the car at all, the EV ratio will still be greater than zero.

 

[BigKeith1962]

Hi Chris,
I understand that it is counting EV while in auto. But often I can go for a long without charging and still get around 30%? :|
A large amount of my driving is motorway miles so I know that the miles traveled are using parallel mode.
Is it just my car that doesn't appear to make sense? Has anyone seen a ratio drop below 30%?

 

[elm70]

In my car, the EV drive ration get reset every second day ... while the fuel consumption is reset more often .. making quite a mess

Anyhow .. many numbers from the MMCS are random ... like the average and instant EV consumption in kwh every 100km ... at list on my old PHEV

The best reference are the numbers from the DOG application :ugeek:

PS: Even when driving long trip on motorway .. I believe I never seen less then 50% EV driving mode on mine ... in my daily usage I have almost all the time 100% EV usage .. anyhow ... it is quite useless .. what matter is the fuel consumption in l/100km .. which has been as bad as 10 or 11L/100km .. since driving at 130km or a bit over (here 140km/h is the allowed max speed), this PHEV does consume quite much fuel

 

[cornclose]

A large amount of my driving is motorway miles so I know that the miles traveled are using parallel mode.
Is it just my car that doesn't appear to make sense? Has anyone seen a ratio drop below 30%?

From what I've seen on my 2019 4HS it looks to be about right.. Even if you do a long journey and end up with a 'flat' battery after the initial EV range has been exhausted, the car still spends some time in EV mode.

Remember, the display shows the time in EV mode as a percentage of overall drive time as opposed to the mileage covered in EV mode. It is surprising how much impact the initial ~25-30 EV miles impacts the overall ratio. Stick some example figures into a spreadsheet and you'll see.

 

[cornclose]

Here's an example;

If I start with a full charge on a say 2 hour journey, I always, as a rule of thumb, say an average of 50 mph is typical in most driving situations. So my 2 hour journey lets say covers 100 miles. The first say 25 miles of that 100 miles will be on EV only. So already the overall time on EV is going to be about 25% (25 miles takes half an hour to cover in this example, and half an hour is 25% of the two hour journey). The remaining 75 miles (90 minutes) will be done in a combination of parallel and series hybrid modes, with the engine running (but not all the time). So if for sake of argument it spends 90% of this remaining time with the engine running and 10% of it on EV mode (using charge derived from the engine when it was running, no idea if this engine on/off ratio is 90/10% but it's probably not far off..) then that's 90% of 90 minutes (81 minutes) running the engine and 10% of 90 minutes (9 minutes) on EV.

So the total time on EV in the 2 hour journey is the original 30 minutes on EV only and the 9 minutes on EV for the remaining 75 miles (90 minutes) of the journey.

So total EV time percentage is ((30 + 9) / 120) * 100) = 32.5% (which would probably show as 33% on the MMC as the mathematical rules is to round up at 0.5 or greater..).

 

[Tipper]

If you have the graphic in front of the driver set to show the three modes of power flow then you can see the hybrid mode changing between EV only, ICE/charging and ICE direct. The car uses all these modes as required to achieve the desired performance.
Also shows the regen during deceleration and braking.

 

[Trex]

Hi All,

.......................................................When I pulled over at the service station I noticed that my EV drive ratio is at 30%.
Has anyone seen this? If so then can you explain how it works as I cannot figure it out.

Hi Keith,

Yes I have and expect to see this. Will bring in a thread I started to help show (probably partly) what I think you are seeing.

I have noticed there is still some chatter about the Charge button. Have seen statements like it will make your fuel consumption worse because it is adding extra conversion processes ie petrol to electricity into battery and battery to electric motors to turn the wheels etc etc.

Now I would, and have, normally discussed this sort of topic in the Technical sections but it is here in General that that I mostly notice this sort of discussion. I think some here may not visit over there or if they do never get involved in the discussions there for "fear" of showing their ignorance on the matter or lack of education in such details. If you feel that way I would suggest taking that first step and asking some questions over there in Technical if you want to learn more about this, I think, wonderful car. There are plenty of members here to help you. Remember we were all new or beginners once. I know I am still learning.

Now back to the topic of the Charge button.

It may come as a surprise to some here that the Charge button is nothing but something the PHEV is trying to do most of the time the petrol motor is running anyway ie charging up the drive battery. That's right, I will say it again, nearly every time the petrol motor runs the PHEV is trying to charge the battery if the load on it is light.

Now that in itself IMO is the hardest thing for us to get our heads around.Why would it try to do that? Sounds inefficient and wasteful of fuel. Charge the battery every time it runs IF it can. Sounds B/S. How does he know this?

I have just spent days reloading some old and new pretty pictures. Lets bring in some because I love pretty pictures and I hope you do too.



Please do not let this graph scare any of you. It is nothing but snapshot of time of a PHEV running along the road travelling at 92.75 kph (see Vehicle Speed row) in Parallel mode. If you do not know what parallel mode is or does please ask. No one worth their salt will jump down your throat IMO.

Now see Engine Revolution going from 2454 revs/min to zero and back up to 2454 revs/min and repeating. That is our PHEV petrol motor starting and stopping as we drive.
I still think it is amazing and I have owned 3 hybrid cars. I still own 2.

Again you can see the Instantaneous Fuel Consumption row. 10.03 Litres of fuel per hour every time the petrol motor runs and then a big fat 0 when it stops.

So what is happening here? It is nothing but Mitsubishi showing us that every time the petrol motor runs in the PHEV if the conditions are right it will CHARGE the drive battery so it can shut down the petrol motor later.

Now another pretty picture. After 2 days of working on them I want to show them off.



Again, do not let some graph frighten you. Ask those questions if you do not understand. There is no such thing as stupid question I think.

So see those squiggly or what are known as sawtooth (look like a saw) lines. Again it is nothing but Mitsubishi showing us the PHEV starting the petrol motor and charging up the Drive battery then stopping the petrol motor and going into EV mode if the conditions are right every time we drive in hybrid mode.

If it so inefficient pushing that Charge button as I have seen some claim here why is Mitsubishi and Toyota with prius etc doing exactly that with their programming of the petrol motor when the conditions are right.

It is because that petrol motor is so inefficient in the first place. Especially under light load conditions eg cruising along at 100kph or 60mph along a flat road and NOT pulling a trailer etc.

A petrol motor is actually at its most efficient when that throttle plate that controls the air to allow for combustion of the fuel is fully open and at certain higher load on the motor. For instance a petrol motor is very inefficient at idle if it was running at the traffic lights when stopped. Unless it was charging a drive battery and even then I would not recommend that. That's another story.

So what does Mitsubishi and Toyota do if the petrol motor needs to run to keep us going and we are just cruising along with a light load on the petrol motor. That right, they increase the load on the petrol motor by generating electricity to be stored in drive battery and after awhile they shut down that bloody inefficient petrol motor and we cruise along in EV mode.

Now that Charge button. All it does is keep the petrol motor going longer and charging up the drive battery for longer than Mitsubishi normally plans. At exactly the same rate as the PHEV normally charges. That is good for building up a charge to climb mountains etc but is also good for avoiding series mode when we come to towns and cities IMO.

But that is another story.

I had better finish here before the moderators chuck me out for putting this in the general section.

I hope it helps and I know I have explained this before over in Technical but just trying to stop what I think are wrong or misleading statements made by some members here.

Regards Trex.

Ps If anyone can help me explain it better please do. I am not a teacher as such. Just a lowly engineer that loves pretty pictures.

What I think you are seeing is explained in that thread. Do not worry that it is about the Charge button ie the Phev charges and EVs as we drive along without the Charge button selected if the loads on the petrol motor are light. Please read the post all the way through and then ask those questions if you do not understand.

But above approx 130 kph there is no more EV mode so what I show above goes out the window IMO.

Regards Trex.

 

[maby]

Hi Chris,
I understand that it is counting EV while in auto. But often I can go for a long without charging and still get around 30%? :|
A large amount of my driving is motorway miles so I know that the miles traveled are using parallel mode.
Is it just my car that doesn't appear to make sense? Has anyone seen a ratio drop below 30%?

I think that the EV ratio display on the PHEV is misleading - I've said so before here. It is simply the ratio of the distance that the vehicle has moved with the petrol engine stopped to the distance that it has moved with the petrol engine running - irrespective of the source of the electricity that was used to move the car with the engine stopped. Once you have run your battery flat, all distance travelled on EV alone is just deferring petrol consumption, and really should not contribute towards the displayed EV ratio. It is certainly true that the hybrid operation of the car once the initial battery charge has been consumed can improve on the fuel economy relative to a similar size car with a petrol engine only, but the improvement is relatively small and getting an EV ratio display of 30% or more on a car that is never charged from the mains is rather misleading.

 

[cornclose]

It is simply the ratio of the distance that the vehicle has moved with the petrol engine stopped to the distance that it has moved with the petrol engine running.

Except it isn't. It is simply the ratio of the time that the vehicle has moved with the petrol engine stopped to the time that it has moved with the petrol engine running.

getting an EV ratio display of 30% or more on a car that is never charged from the mains is rather misleading.

On the contrary, it would appear to be fairly accurate from my own measurements.

 

[elm70]

EV ratio could be very different per the firmware version of the MMCS

I believe I have the oldest possible firmware on this PHEV

In my case the EV ration does not change when I switch between manual and automatic (so from short history data to long history data) .. while the fuel consumption does change value (currently in my last 3000km I have 0.3L / 100km)

In my case the EV ration does remember data from the previous day ... I'm running almost all time in EV mode ... except when I make a long trip or a mistake on pressing too much the accelerator .. so normally I have 100% EV ratio .. but I can still see less then 100% EV ration on the next day after I made a long trip or I had an accidental over acceleration with ICE start

Anyhow ... I find the EV ratio a useless information .. except for show me up if I made a mistake and I kick in the ICE in the last 30h

Like the average EV consumption in kwh/100km ... these are totally random numbers in my MMCS

 

[maby]

It is simply the ratio of the distance that the vehicle has moved with the petrol engine stopped to the distance that it has moved with the petrol engine running.

Except it isn't. It is simply the ratio of the time that the vehicle has moved with the petrol engine stopped to the time that it has moved with the petrol engine running.

getting an EV ratio display of 30% or more on a car that is never charged from the mains is rather misleading.

On the contrary, it would appear to be fairly accurate from my own measurements.

Whether it is the ratio of distance or time seems fairly immaterial to me - my point is that you could take delivery of a brand new PHEV, never connect it to an external charger and a year later it will be telling you that you have driven 30% on EV. That is misleading as far as I'm concerned - all the distance you've driven has been achieved by burning petrol - just that 30% of that petrol consumption was deferred by a few minutes.

 

[Trex]

............................................ my point is that you could take delivery of a brand new PHEV, never connect it to an external charger and a year later it will be telling you that you have driven 30% on EV. That is misleading as far as I'm concerned - all the distance you've driven has been achieved by burning petrol - just that 30% of that petrol consumption was deferred by a few minutes.

Now IMHO I like to see how efficient the PHEV has been and by seeing that EV ratio while burning fuel ie the closer to 100% that ratio is the more efficient the PHEV has been running ie better fuel consumption. Its showing just how much that bloody inefficient petrol motor (to me all ICE engines are inefficient when compared to batteries, electric motors etc) has been shut off.

So why do you think it misleading? Sure fuel, and some regen, has been used to make that EV ratio (once the grid charge has been used) but it was fuel used to generate electricity plus drive the front axle when in Parallel mode. Remember it is Hybrid Electric Vehicle (HEV). It tells us that that by putting the petrol engine in its efficient "zone" by generating electricity it can shut the petrol engine off approx 40% of the time for me on long trips ie it acts like a extreme overdrive ratio IMO. I use that EV ratio to tell me my average RPM of the petrol motor at certain speeds and at a certain SOC in the drive battery.

BTW the way the PHEV is set up, for me, it acts like it has a 3 speed auto gearbox in Parallel mode at the speeds I can travel here on the highway. 1. Light loads on the petrol engine it acts like it has overdrive, 2. heavier loads like climbing hills it boosts with battery and 3. extra heavy loads it go back into Series mode. All done with a one speed gearbox. Yes, I like simple or minimalistic HEVs.

 

[STS134]

So why do you think it misleading?

That entire screen is misleading. First of all, I'd really care more about the distance traveled using wall power vs. gasoline power, and second, well, take a look at this. I mean, really? There's absolutely NO WAY this could be true. I rarely ever check the numbers on that screen because it's just a bunch of BS and I have no idea what the computer is doing to calculate that stuff but whatever it's doing it's wrong.

 

[Trex]

So why do you think it misleading?

That entire screen is misleading. First of all, I'd really care more about the distance traveled using wall power vs. gasoline power, and second, well, take a look at this. I mean, really? There's absolutely NO WAY this could be true. I rarely ever check the numbers on that screen because it's just a bunch of BS and I have no idea what the computer is doing to calculate that stuff but whatever it's doing it's wrong.

Hey, where is that "IMO" or "I think" we talked about? You should try and control your emotions IMHO or stop trolling me if you want me to help you or explain how the PHEV works.

 

[greendwarf]

It is simply the ratio of the distance that the vehicle has moved with the petrol engine stopped to the distance that it has moved with the petrol engine running.

Except it isn't. It is simply the ratio of the time that the vehicle has moved with the petrol engine stopped to the time that it has moved with the petrol engine running.

getting an EV ratio display of 30% or more on a car that is never charged from the mains is rather misleading.

On the contrary, it would appear to be fairly accurate from my own measurements.

Whether it is the ratio of distance or time seems fairly immaterial to me - my point is that you could take delivery of a brand new PHEV, never connect it to an external charger and a year later it will be telling you that you have driven 30% on EV. That is misleading as far as I'm concerned - all the distance you've driven has been achieved by burning petrol - just that 30% of that petrol consumption was deferred by a few minutes.

What about coasting i.e. no fuel or leccy used?

 

[maby]

............................................ my point is that you could take delivery of a brand new PHEV, never connect it to an external charger and a year later it will be telling you that you have driven 30% on EV. That is misleading as far as I'm concerned - all the distance you've driven has been achieved by burning petrol - just that 30% of that petrol consumption was deferred by a few minutes.

Now IMHO I like to see how efficient the PHEV has been and by seeing that EV ratio while burning fuel ie the closer to 100% that ratio is the more efficient the PHEV has been running ie better fuel consumption. Its showing just how much that bloody inefficient petrol motor (to me all ICE engines are inefficient when compared to batteries, electric motors etc) has been shut off.

So why do you think it misleading? Sure fuel, and some regen, has been used to make that EV ratio (once the grid charge has been used) but it was fuel used to generate electricity plus drive the front axle when in Parallel mode. Remember it is Hybrid Electric Vehicle (HEV). It tells us that that by putting the petrol engine in its efficient "zone" by generating electricity it can shut the petrol engine off approx 40% of the time for me on long trips ie it acts like a extreme overdrive ratio IMO. I use that EV ratio to tell me my average RPM of the petrol motor at certain speeds and at a certain SOC in the drive battery.

...

I would not disagree that the proportion of the time running with the petrol engine off is an interesting figure, but I do think that describing it as "The EV ratio" is misleading. As has been demonstrated very strongly on this forum, a high proportion of PHEV owners seek to minimise petrol consumption - to the extent of pulling fuses to disable the engine and driving in multiple layers of clothing in order to avoid having to turn the heater on. While you have charge left in the battery from the last mains hookup, you have the potential to remain 100% EV provided you adopt the right driving style - that, I believe, is what most ordinary people would understand by "EV ratio". Once you have completely exhausted the charge that you took on from the mains, then you are driving a petrol car with an electrical transmission. The battery is providing a reservoir to buffer charge which was accumulated by running the engine at its peak efficiency rather than simply setting it to output the power level necessary to maintain your road speed but I maintain that recording those periods of consuming surplace energy from the battery on the same gauge that is also used to report the relative use of petrol and mains derived power is misleading.

Look at it this way - my normal pattern of usage is a round trip of about 250 miles each week with a few more miles done locally at weekends. As you know, I am unable to charge during that 250 mile round trip, so the car gets a mains charging once or twice per week. I get about 20 miles from a charge - perhaps 25 in the warm weather - so, in my book, the EV ratio of my car is around 10%, possibly a bit lower. Another driver with the same car, but a different lifestyle, could come close to never burning petrol at all. Greendwarf lives in London and uses his PHEV almost exclusively for short range commutes. My PHEV generally reports EV ratios between 30 and 40% - I guess that his generally reports something closer to 90%. Is his usage just two or three times more fuel efficient and ecological than mine? Of course not! My fuel consumption and carbon footprint are similar to what I would achieve with a similar sized pure petrol vehicle while his must be pretty close to zero.

 

[ThudnBlundr]

Whether it is the ratio of distance or time seems fairly immaterial to me - my point is that you could take delivery of a brand new PHEV, never connect it to an external charger and a year later it will be telling you that you have driven 30% on EV. That is misleading as far as I'm concerned - all the distance you've driven has been achieved by burning petrol - just that 30% of that petrol consumption was deferred by a few minutes.

The whole point is that it is not the same as if you'd driven on petrol alone. As stated in the post above, when cruising on a motorway, an ICE is actually even more inefficient than usual. So a normal 2l engine driving the front wheel would be less efficient than the PHEV. The PHEV gets round this by changing the ICE to burn petrol at a more efficient level, and using the excess power generated to produce electricity. So the EV mode is celebrating the extra energy released by driving in this way.

 

[Tai626]

My understanding on the EV ratio is for maintenance purpose.

30% EV in 300miles trip (considering 60mph flat surface) means 210 miles using engine to be considered when I would change the spark plug, for example.

The other 90miles should be considered for the battery SoH. 3 cycles on this trip, maybe, out of 2000+ total cycles that our batt have in all its serviceable life.

Tai

 

[STS134]

So why do you think it misleading?

That entire screen is misleading. First of all, I'd really care more about the distance traveled using wall power vs. gasoline power, and second, well, take a look at this. I mean, really? There's absolutely NO WAY this could be true. I rarely ever check the numbers on that screen because it's just a bunch of BS and I have no idea what the computer is doing to calculate that stuff but whatever it's doing it's wrong.

Hey, where is that "IMO" or "I think" we talked about? You should try and control your emotions IMHO or stop trolling me if you want me to help you or explain how the PHEV works.

Any time I see a value over 50 mpg, and I was driving on flat terrain, it's just so unrealistic that it's misleading. And this is higher than that by a factor of over 18. It appears to be accounting for distance traveled/fuel burned, and not accounting for the fact that electricity from the battery was used to propel the car for most of the distance. In this particular case, the engine was already warm when I started the trip, and the engine started up for a brief moment when I floored it. I then stayed in EV mode the rest of the trip, and the mpg meter just kept going higher and higher. So what does that number mean? What does this say about the number of miles I'd be able to go for every gallon of gas burned in the steady state (Save mode or battery empty)? Absolutely nothing. It's useless.