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PHEV - Questions and Advice

Posted: Mon Jun 10, 2019 1:22 pm
by StuartMaher
Hi All,

We just got a brand new PHEV and I had a couple of questions and was looking for some advice.

Firstly, from reading other posts here, Am I to assume that just day to day use in EV mode will still incur a petrol overhead as certain things cause the ICE (internal combustion engine?) to kick in, such as the Air Con? Is this correct, is there a way of telling if the engine has come on? I'm assuming this is at very low levels, just to act as a generator so you don't kill the car battery? What other devices will cause the ICE to kick in and is there a dashboard indicator to tell you it is running?

Secondly, the main advice I am looking for is how to use the car on longer journeys? For the most part the car will be used EV only as we would rarely do more that 30 miles in a day. However the odd occasion will come when we have to do a few hundred miles in one go. Is the best plan, to start fully charged and do the 200 miles in HEV mode, or run 35 miles in EV and then let HEV kick in. Basically, is HEV more economic on a full charge?



Re: PHEV - Questions and Advice

Posted: Mon Jun 10, 2019 7:10 pm
by radar2018
You will find that the petrol engine hardly ever runs unless you accelerate very fast going uphill, in winter you are correct it needs to run for AC, I am not sure about the AC in summer. I have not found any indication that the ICE is running other than the sound.

I am not sure I understand the last question, the impression I get is that the battery acts as 2 batteries the top bit for EV and the little bit at the bottom for HEV, once the battery for EV is used , the HEV does not top it back up, Although in SPORT MODE there is some EV recovery.

I have done 3500 miles and only charged at home, on a long journey I just use up the EV miles then the HEV takes over, I have not gotten round to charging away from home.

I am sure if I have given you the wrong information someone will correct me, and then I will be wiser too.

Re: PHEV - Questions and Advice

Posted: Tue Jun 11, 2019 1:46 am
by jerrytaff
It seems that the ICE is only needed with the aircon when it is being used for heating the car.

As far as electric use strategy is concerned, I think it best to use at least part of the electric charge first. That way you can still get the regen effects when coasting or braking downhill - if the battery is already fully charged it won't try to overcharge it, so the energy is lost (and presumably the friction linings on the brakes have to be used). So to answer your question, I believe that HEV is less efficient on full charge, and that it only needs a relatively small amount of charge in the battery to operate as efficiently as it can.

The rest is less clear cut, although my impression is that the the electric motor is more efficient than the ICE at low speeds, and the ICE is the more efficient at motorway speeds. Certainly, I can get close to the indicated electric range of 36 miles when pootling around town, but only about half that on the motorway. By contrast, on a recent holiday when I did not have the opportunity to charge the battery, so was only using it in HEV mode the fuel economy did not vary greatly between town, constant mid-speed runs and fast motorway driving (the range of values was between about 55 and 63 mpg)

So, my strategy on longer trips is to switch from EV mode to HEV when accelerating onto a motorway slip-road, to preserve some EV capability for when stuck in slow moving traffic and for driving in town after leaving the motorway. However, I modify that approach to ensure that I run the EV range down to zero 4 or 5 miles before reaching home (or to wherever I am going to charge the car). The reasons for that are that although it is obvious that its pointless burning petrol when there is still EV capability, it isn't quite so obvious that the car will travel a couple of miles on 0 miles EV range before automatically switching to HEV mode, and even then, it will be still running the battery down further for a while by flicking in and out of EV mode while continuing to display 0 miles EV range. If I put it on charge using the granny cable (13A socket but charging at 8A) when it has just automatically switched to HEV mode it only takes 3hrs 45 minutes to charge, whereas after an extended drive after that switch, it takes 4hrs 5 minutes to recharge. This indicates that I have effectively got another 3 miles of electric range after it switched to HEV mode.

Like Radar2018, I don't pretend that his answer is definitive, and if anyone knows different I too would like to know.

Also, I recently found myself driving down some long extended slopes for the first time since I've had the car. So now I have a question. Should I select a low gear and use engine braking, should I gently use the brakes and rely on the electric regen via the motor to control the speed - if so how do I know that I'm not using the brake linings and cooking the brakes? - , or should I select the speed I want on the cruise control and get the car to work it all out for me?

Re: PHEV - Questions and Advice

Posted: Tue Jun 11, 2019 5:54 am
by radar2018
When you got your car was KIA not installing a charge point for free, I could have had one fitted but I tried to get them to fit an alternative charger.
As we have SOLAR I wanted to fit a charger to take advantage of all the surplus power we were producing on bright summer days, yet not take power from the grid when a cloud passed over the sun.

I am still at a loss to figure out exactly how to use SPORT MODE to any great advantage

Re: PHEV - Questions and Advice

Posted: Tue Jun 11, 2019 11:45 am
by jerrytaff
(Just noticed the typo in my previous post. Meant to say "I don't pretend that this answer is definitive")

They stopped doing the free charger between my test drive and making the purchase. However, in the end I bought a low mileage 6 month old ex-demonstrator. As it wasn't a purchase from new, the offer wouldn't have applied anyway.
I also have solar power; a 2.7kW array; east facing so I get the sun early in the morning. At this time of year I try to charge from the solar as much as possible by looking at the weather forecast and setting a timed charge from whenever I think it might be sunny. Far less scientific than using an intelligent charger, I know, but on a good day, I can charge at 8A entirely off the solar. On other days I could set a lower charge rate, but can't usually be bothered.

As far as sport mode is concerned - there are actually 2 modes. Sport when in EV mode gives amazing acceleration; It holds the low gears for longer, and more readily uses the ICE to augment the power. It actually results in 0 to 60 times far faster than the Kia spec! Sport in HEV mode seems to be just a switch to semi-automatic; holding the car in gear until the next is manually selected or until the car over-rides you to avoid rev limiting or labouring excessively.

The first mode is good fun but fuel inefficient. Very useful though for overtaking; the car accelerates better than if you were just to kick down on the accelerator.

The 2nd mode is very difficult to make sensible use of; there is no rev counter, and from memory I think I'm correct in stating that you don't even know what gear the PHEV is in. The display just says "S". So, knowing when to change gear is a bit of a challenge, and I don't use it. Apparently you can use that mode, running the engine at high revs to get extra charge in the battery for EV use, but burning large amounts of excess petrol to generate some electricity so that you can avoid burning small amounts of petrol later seems to be a particularly pointless exercise.

Re: PHEV - Questions and Advice

Posted: Tue Jun 11, 2019 7:07 pm
by MerlinXL
My experience over 12000 miles with the PHEV is slightly different.
I use EV mode in built up areas to help reduce pollution and HEV mode on motorways.
A recent trip Burnley to Penzance and back averaged 60mpg in HEV mode (8.8p/mile)
In comparison EV mode in now costs about 3.3/mile
Sports mode is useful for overtaking and joining motorways and does recharge the batteries for use in built up areas to come.

My senses tell me sports mode effect is the same in HEV or EV.

Using manual shifts seems a waste of time except for slowing the car down on descents. When the rev limit is reached (I assume) it still changes up automatically.

One thing to look out for on the PHEV though, once the battery is down to 0 miles then sports mode will only go into manual mode not auto mode, so watch the revs.
Page 6-21 last paragraph refers.

Re: PHEV - Questions and Advice

Posted: Wed Jun 12, 2019 8:56 pm
by JOL54
2 modes in EV sport? When I move lever to sport position it goes to HEV automatically and engine cuts in? How do you get sport mode in EV please?

Re: PHEV - Questions and Advice

Posted: Thu Jun 13, 2019 9:56 am
by jerrytaff
There's a lot of confusion here....

There are 2 "Sports" modes - one where the gearchanges are automatic, and one where you have to make them manually. I thought that HEV mode always resulted in having to make the manual gearchange, but MerlinXL seems to think that only happens once down to 0 miles EV range.

In my Owners Manual, page 6-21 on the right hand side it says

-For Plug-in hybrid vehicles.
  • If the vehicle is in Electric (CD) mode and you shift from D (Drive) to S (Sport) the vehicle will change to SPORT mode. In SPORT mode, if you move the lever up (+) or down (-), the vehicle will enter manual shift mode .
  • If the vehicle is in Hybrid (CS) mode and you shift from D (Drive) to S (Sport) the vehicle will automatically enter manual shift mode.
So we have some new terminology Electric (CD) mode and Hybrid (CS) mode. Page H3 has CD as Charge Depleting Mode and CS is Charge Sustaining Mode. It could be interpreted that CS mode is only entered after the EV range has been depleted; although if you select HEV mode before then, the effect is also to sustain the charge. So I'm more confused than ever - but its about a mode I never use. Also, I think I was wrong about the gear not being displayed.

It looks like some testing / experimentation is in order

Re: PHEV - Questions and Advice

Posted: Thu Jun 13, 2019 9:59 am
by jerrytaff
Oh and by the way, Sports mode (CD) does use the engine. That's where the additional power comes from, but I think it holds the low gears longer too to improve the acceleration further.

Re: PHEV - Questions and Advice

Posted: Thu Jun 13, 2019 12:39 pm
by radar2018
I am certainly confused by this SPORT MODE, a while back I had a 24 mile journey there and back, when I got almost there (23 miles) I had to go off road, in order to keep the speed down I switched to SPORT and the car set in 2nd, I reduced speed back to 1st (1 mile there 1 mile back) the EV mileage increased 5 miles on the display. On the way back it switched to HEV 9 miles from home. The petrol mileage reduced 13 miles.
At the time I was confused, even more so now, as I have done the same journey twice since and had much different results, once with no increase in EV mileage.

I find that the petrol mileage fluctuates up and down, without actually using HEV

I know that is not the intended use of SPORT which is for increased acceleration
I am very pleased with the car although I must admit I know less about how it works than any other car I have had, and my driving has changed I always feel more relaxed and hardly ever in a hurry