Can we clear up Serial vs Parallel drive?

[Fjpod]

I've read most of the posts, forgive me if I missed one that explains it....

Everyone seems to be saying that Parallel drive mode is more energy efficient. I haven't seen a difference in instantaneous fuel consumption or acceleration power. (Generally, I feel the Outlander PHEV acceleration is "great" considering what it is).

The car seems to choose whether it wants Serial or Parallel on its own. Nothing I do seems to make a difference going into whatever mode it uses.... whether I press the accelerator minimally or firmly. Going uphill or downhill... it seems to do what it wants....not what I think it should do.

Anybody have insight into this? I do not tow anything. Mostly suburban stop and go driving, with occasional highway driving. My questions center mostly around highway driving.

 

[user 3575]

https://www.richi.uk/p/mitsubishi-outlander-phev-faq.html#phevfaqK

 

[Fjpod]

Thanks for the link. It does clear up a lot of things.

It does not support the assertion made by many here that parallel mode is more efficient than series. So, do we still have confusion?

 

[ChrisMiller]

Direct mechanical drive is likely to be more efficient than an indirect electrical one, which involves extra stages with inevitable losses occurring at each. Anyway, if it wasn't more efficient, why would the Mitsubishi engineers have included it? It must surely carry some weight penalty.

 

[Fjpod]

Direct mechanical drive is likely to be more efficient than an indirect electrical one, which involves extra stages with inevitable losses occurring at each. Anyway, if it wasn't more efficient, why would the Mitsubishi engineers have included it? It must surely carry some weight penalty.

For more power?

 

[jaapv]

I suggest you browse the forum. There have been discussions and explanations for serial vs parallel hybrid, including graphs, ad nauseam.
The short answer is: the Mitsubishi solution, including the software controlling it, is quite efficient.

 

[littlescrote]

For more power?

How do you suppose that you can get more power out of the engine when it is linked to the road wheel speed in Parallel mode than when it is free to rev higher in Series mode? As with pretty much every engine ever built, (generally) more revs = more power

For any given rpm, there will be slightly more power available at the wheels when in parallel mode due to the explanation of losses above, but that's it.

 

[ChrisMiller]

To deliver more power than the 160bhp* available in serial mode, the car speed (i.e. the equivalent engine revs) needs to be over 75mph/120kph. You can demonstrate this (on a straight, empty road!) by flooring it - the car will remain in serial mode up to this speed. To achieve the maximum power (200bhp) in parallel mode, you would need to be doing almost 100mph.

* from the 2x60kW electric motors (slightly more in the latest version with the 2.3l engine)

 

[Tai626]

Parallel mode is possible at speed > 45mph. My trick is “release” the torque in the transmission like I change gear in my bicycle. It works every time if the engine is warm Enough in the “charge mode”.

Tai

ps. Try search for the “series” instead of “cereal“

 

[jaapv]

Yes, but it is not very efficient. The low engine revs mean that the ICE is delivering little power, and well outside its most effective rev range as well.

 

[Tai626]

I think it is the reason the recent Outlander adopted Atkinson Cycle for better efficiency at broader RPM.
Even at Otto cycle, the extra torque go to batteries so it cannot be less efficient than series drive.
What I learnt to drive more efficiently is to use up 1/2 of batteries and go to parallel as fast as you can. It may involve some bottom pressing but it is fun. The car owner (my wife) may have another opinion about too much piano playing on her car

Tai

 

[Tipper]

I think it is the reason the recent Outlander adopted Atkinson Cycle for better efficiency at broader RPM.
Even at Otto cycle, the extra torque go to batteries so it cannot be less efficient than series drive.
What I learnt to drive more efficiently is to use up 1/2 of batteries and go to parallel as fast as you can. It may involve some bottom pressing but it is fun. The car owner (my wife) may have another opinion about too much piano playing on her car

Tai

But it's not a true Atkinson engine...it's solely manipulation of the variable valve timing.

An Atkinson engine is much more complex than that involving changes to piston timing.

 

[user 3575]

http://www.curbsideclassic.com/wp-content/uploads/2012/10/Atkinson-anim-6.gif

 

[Tai626]

Now we have computer to switch cycles from Otto to Atkinson

From Toyota marketing:

https://m.youtube.com/watch?v=gD2AQuhbHdk

I think the 2.4L only runs Atkinson at lower speed. At higher speed, the engine switch to Otto cycle to supply the power needed.

We don’t get the 2.4L here in North America yet so please don’t quote me

The Eclipse Cross PHEV is not coming here in 2021 neither ...

Tai

 

[kehfunah]

I'm very new to the phev. Just bought a 2020 phev and still don't understand how to use the serial and parallel drive. How do I select this? I only see normal mod, ev mode, eco, charge and save.

 

[ChrisMiller]

The car does it for you, depending on how much power you demand and your speed - it's all clever electronics and you have relatively little control over the power mode. You get a visual indication of which mode it's in either from the larger panel in the middle of the dash or the smaller panel in front of the steering wheel.

 

[jaapv]

You can influence this more or less by the accelerator.

 

[ThudnBlundr]

You have no control exept the speed you are going. Above 40mph/65kph the car will try to go into Parallel unless you are accelerating hard or are using 'Sport' mode. It connects the ICE to the wheels using what is in effect a top gear. Below that speed it has to use Series as the ICE would not be able to be run in an economical mode

 

[MadTechNutter]

I am driving a late 2014 model so what I write may not be applicable to the newer models mentioned here. Also the ICE must have been running about one minute before it will switch to parallel mode.
As I mostly (99% of the time) drive in EV mode I am weary about demanding a lot of power/revs from a cold ICE, so I don't 'floor' it unless it has been running a while.

Parallel will always be more efficient than series so if one wants low fuel consumption, you want to achieve that 75km/h switching point ASAP (where safe) and then lift the throttle back where in my case I can keep it in parallel down to 65km/h (speedo shows 3km/h too high), so 62km/h, nobody will book me for that in a 60 zone.
Accelerating from that low speed will drain from the battery rather than switching to series again unless you floor it.

However I always try to drive pure EV mode at speeds up to 80km/h and only press the charge button when I am over or know I will be driving longer at 80km/h so I can avoid the dreaded series mode.

Now when you can't avoid series going up a steep hill, I find it better to switch to battery save rather than charge to avoid racing the ICE.
This can't be good for the engine nor for the battery when it is revving that high.
When I switch to save it runs quiet and I feel I have the same climbing torque.
I don't know if this is an error just with my car or a general design issue that the engine overworks itself by achieving the power for the hill and energy for the battery charge but it sounds so wild like the cylinder head is about to blow in the charge setting.
This is a vey steep hill, maybe 30˚ at times going up with 60km/h.

 

[littlescrote]

you're being overly worried about nothing. the engineers knew what they were doing when they programmed it.

the engine really doesn't rev very high, nowhere near what you might rev it to in a manual, and as it's the same basis of engine to the Lancer Evolution models, it's a well proven unit. the cylinder head is not going to blow unless you haven't serviced it and changed and filled fluids correctly, and even then generally you'll have some warning lights before anything mechanical happens. not going to happen unless it's been seriously abused in terms of lack of service.