Mitsubishi Outlander PHEV Forum

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 Post subject: Re: So why do we have Hybrid Electric Vehicles.
PostPosted: Sun Jan 06, 2019 4:43 pm 
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Location: Near Port Macquarie Australia
STS134 wrote:

But you make it sound like 40% efficiency is horrible, when in fact it is not.


No I agree. 60% losses are good. So for every $1 of fuel I put in the engine I get 40 cents back in usable energy at the best. No you are right, that is good. :?

BUT you also said elsewhere:
STS134 wrote:
First of all, each round trip through the battery costs about 10-20% in energy, at least. That's not efficient.

and
STS134 wrote:
But still, all else being equal, a HEV will have better efficiency than a comparable performance ICE only car, even if both vehicles can do 0-60 in 4.5 seconds, simply because the HEV can keep the engine in its optimal power band for much more of the time, and can recover energy when braking.

So when the PHEV charges its drive battery to put it into its "optimal power band" (so it can shut down the ICE later) you say its inefficient but then you say "HEV will have better efficiency than a comparable performance ICE only car...because the HEV can keep the engine in its optimal power band". :? You are starting to sound a bit inconsistent I think or have I started to change your mind? IMO through research and learning it quite ok to admit you were wrong and change your mind about things.

In a thread where I am writing about Hybrid Electric Vehicles which is naturally comparing the advantages and disadvantages of different drivetrains ie electric and petrol most people here I would hope can see where I am going with that statement about the ICE being inefficient or as I say bloody inefficient.


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 Post subject: Re: So why do we have Hybrid Electric Vehicles.
PostPosted: Sun Jan 06, 2019 5:30 pm 
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Location: Near Port Macquarie Australia
STS134 wrote:
Now as far as downsizing the ICE is concerned, this is NOT necessary to take advantage of HEV technology, and IMO Toyota overdid it, especially in the Prius. The Prius isn't a PHEV, and has a small battery, which gets quickly exhausted when climbing steep hills. Thus, the ICE should still be designed to match peak load when climbing, not average load when cruising. Whoever designed the thing must not have ever had to climb long slopes.


I think that it good to see that IMO in your statement there. ;)

Like I said earlier in this thread:

Trex wrote:
Now why did Toyota produce the Prius which no matter what we think of them Toyota has sold millions. Edit approx 6 million up to 2016 from what I can see including all variants.


Notice that "all variants" I wrote there, well included in that is the Plug-in Prius and Prius Prime which I would consider to be PHEVs.

Now as a person that owned and driven a Prius climbing the Great Dividing Range here it was quite ok performance wise even once the battery was down but mine was a Gen 3 so it had the bigger petrol motor compared to previous models.


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 Post subject: Re: So why do we have Hybrid Electric Vehicles.
PostPosted: Sun Jan 06, 2019 6:11 pm 
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Joined: Thu Feb 26, 2015 5:58 pm
Posts: 735
Location: Near Port Macquarie Australia
Tai626 wrote:
HEV is no always about the efficiency. Look at this $2.2 Mi Mega Car:
https://en.m.wikipedia.org/wiki/Koenigsegg_Regera
Where Batt+Motors are for torque! The “simplicity” of a power train without transmission comes as a bonus.
Just imagine we mod the PHEV engine to EVO spec (330kW) paired with 2x350kW motors. It would be considered as a Mega(Watt) car as well.
Tai


Hello fellow manly ute oops :oops: truck owner.

Yes that definition I put in my first post in this thread states "The presence of the electric powertrain is intended to achieve either better fuel economy than a conventional vehicle or better performance."

$2.2 mil. :o Can buy a lot of PHEVs for that. ;)

Mega(Watt) :lol: :lol:


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 Post subject: Re: So why do we have Hybrid Electric Vehicles.
PostPosted: Sun Jan 06, 2019 6:38 pm 
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Posts: 141
Location: Saratoga, CA
Trex wrote:
No I agree. 60% losses are good. So for every $1 of fuel I put in the engine I get 40 cents back in usable energy at the best. No you are right, that is good. :?


You've gotta compare to the best efficiency that is even possible, which is the Carnot efficiency. Then, you remove the isothermal expansion and contraction stages (not possible in a car engine, because the power to weight ratio of such an engine would suck) and you get some value for the maximum efficiency that is possible in a practical ICE. In that regard, 40% isn't that bad at all.

Trex wrote:
So when the PHEV charges its drive battery to put it into its "optimal power band" (so it can shut down the ICE later) you say its inefficient but then you say "HEV will have better efficiency than a comparable performance ICE only car...because the HEV can keep the engine in its optimal power band". :? You are starting to sound a bit inconsistent I think or have I started to change your mind? IMO through research and learning it quite ok to admit you were wrong and change your mind about things.


So...here's the thing. When I tell the PHEV to charge the battery, i.e., I put it in Charge mode, and it runs the ICE in a very efficient power band by using some power to propel the vehicle and some to charge, great. If I just ask it to Save battery power, and DO NOT want it to charge the battery, nor draw power from it, it would be much better if it simply lowered the ICE RPM to operate the ICE in at an efficient RPM for the power being demanded of it, that is, the power level required to propel the car only. Which would require a mechanical transmission to do.

Trex wrote:
In a thread where I am writing about Hybrid Electric Vehicles which is naturally comparing the advantages and disadvantages of different drivetrains ie electric and petrol most people here I would hope can see where I am going with that statement about the ICE being inefficient or as I say bloody inefficient.

Yeah but I think people overestimate how bad ICE efficiency is. At a power plant, the heat engine there is also limited by the Carnot efficiency, and while those engines aren't constrained by size or weight the way a vehicle engine is, such an engine suffers from transmission losses associated with sending power from the engine to the ultimate user of it over the grid.

Trex wrote:
STS134 wrote:
Now as far as downsizing the ICE is concerned, this is NOT necessary to take advantage of HEV technology, and IMO Toyota overdid it, especially in the Prius. The Prius isn't a PHEV, and has a small battery, which gets quickly exhausted when climbing steep hills. Thus, the ICE should still be designed to match peak load when climbing, not average load when cruising. Whoever designed the thing must not have ever had to climb long slopes.


I think that it good to see that IMO in your statement there. ;)

Like I said earlier in this thread:

Trex wrote:
Now why did Toyota produce the Prius which no matter what we think of them Toyota has sold millions. Edit approx 6 million up to 2016 from what I can see including all variants.


Notice that "all variants" I wrote there, well included in that is the Plug-in Prius and Prius Prime which I would consider to be PHEVs.

Now as a person that owned and driven a Prius climbing the Great Dividing Range here it was quite ok performance wise even once the battery was down but mine was a Gen 3 so it had the bigger petrol motor compared to previous models.


I'm guessing that you never tried to do a run up the Grapevine on I-5 (6% grade for 5 miles straight) at 80+ mph. https://priuschat.com/threads/highway-m ... ls.124036/ People are reporting that it had trouble maintaining 60 mph with the accelerator floored once the batteries drained (post #20 and #21). That's the problem with sizing the ICE for average power AND having batteries that are insufficient to maintain peak power over the passes. The maximum speed I ever reached in my previous car up that grade though, was around 88 mph with the accelerator at WOT (wide open throttle) nearly the entire way up. I feel like the PHEV *could* do it, but you'd better have at least 60% charge when you get to the bottom (I only did around 75-80 mph up the grade last time because that's the speed at which most traffic was moving). At least Mitsu optimized the fixed ratio to generate maximum ICE power at 90 mph, which is great for running up the grade at high speed and actually getting maximum output from the ICE. But when you get to the top, expect your hottest cell to be at 34C with the cooling system running, even if it's cold outside. I wish it could do it without abusing the battery so much though.


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 Post subject: Re: So why do we have Hybrid Electric Vehicles.
PostPosted: Sun Jan 06, 2019 7:23 pm 
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Joined: Thu Feb 26, 2015 5:58 pm
Posts: 735
Location: Near Port Macquarie Australia
STS134 wrote:
You've gotta compare to the best efficiency that is even possible, which is the Carnot efficiency.


Au contraire. IMO I have not "gotta" even think about the Carnot cycle or efficiency which I covered in my engineering training over 30 years ago because in this topic I am comparing it to electric motors and batteries etc. Hence my statement :
Trex wrote:
If you have to start that petrol motor run it in its most efficient "zone" and at all other times try and turn the bloody inefficient petrol motor off.

Which I mean to be in EV mode when that bloody inefficient petrol motor is off. I hope that was clear to everybody.


Last edited by Trex on Sun Jan 06, 2019 10:05 pm, edited 1 time in total.

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 Post subject: Re: So why do we have Hybrid Electric Vehicles.
PostPosted: Sun Jan 06, 2019 8:43 pm 
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Joined: Thu Feb 26, 2015 5:58 pm
Posts: 735
Location: Near Port Macquarie Australia
STS134 wrote:
I wish it could do it without abusing the battery so much though.


You can, by slowing down. Have you tried to force it into series mode? But you would have to be under about 120 kph.

Watch this video to see what I mean.
https://www.youtube.com/watch?v=rbOmtzFj14M

Watch center display between power gauge and speedo gauge and see how it goes from Series mode into Parallel mode at about 120kph.


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 Post subject: Re: So why do we have Hybrid Electric Vehicles.
PostPosted: Sun Jan 06, 2019 11:39 pm 
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Joined: Mon Sep 26, 2016 11:18 pm
Posts: 981
Location: Poland
Trex wrote:

Yea I still think it is amazing what hybrids can do and I have owned 4 of them. I had a BMW 5 series that could get 30 mpg imperial and I thought that was fantastic. It was smaller (less drag), less weight and a 2wd as compared to the PHEV but the PHEV for me comfortable beats it and, like you, that is not counting the grid charge.


My previous BMW 320d was doing over 50mpg at 130km/h speed

If you care of fuel economy a diesel and a sedan offer superior economy

Since we opted for a SUV ... I guess fuel economy is a secondary factor.


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 Post subject: Re: So why do we have Hybrid Electric Vehicles.
PostPosted: Sun Jan 06, 2019 11:47 pm 
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Joined: Mon Sep 26, 2016 11:18 pm
Posts: 981
Location: Poland
Trex wrote:

I cannot stand how the i3 looks. It just looks too different to me. Which over here would be an attraction for the anti EV and hybrid brigade to key it (scratch it using their keys) while you were not around. That's why I like the PHEV. It looks the same as the standard Outlander with just minor differences that goes mostly unnoticed over here.

I do not need a bigger battery as I am already carrying around battery that's probably about twice as big as needed for our average purpose. The PHEV as is serves us very well and that is why I have bought 2 of them but I look forward to any improvements like the Atkinson cycle petrol motor, longer life drive batteries etc.

Edit From memory the i3 Rex runs only in series mode from memory. So less efficient IMO.


I did refer to i3 power system, not the look :ugeek:

A bigger battery will help not only on longer EV range, but as well on be able to provide more power (now it is limited to 70kw for the latest PHEV, old one has 60kw) ... as well, it will be less under stress and should be able to keep the SOH better then current PHEV which has a problem in this area

About series mode to be inefficient ... well ... it is in our current PHEV .. on a proper REX system I bet it can be quite efficient, if the small engine is tuned to deliver power at a given power level which is the ideal working load for this ICE


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 Post subject: Re: So why do we have Hybrid Electric Vehicles.
PostPosted: Mon Jan 07, 2019 12:30 pm 
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Joined: Wed Jul 11, 2018 4:35 pm
Posts: 141
Location: Saratoga, CA
Trex wrote:
STS134 wrote:
I wish it could do it without abusing the battery so much though.


You can, by slowing down. Have you tried to force it into series mode? But you would have to be under about 120 kph.

Watch this video to see what I mean.
https://www.youtube.com/watch?v=rbOmtzFj14M

Watch center display between power gauge and speedo gauge and see how it goes from Series mode into Parallel mode at about 120kph.

Yes but I've found that once it goes into parallel mode, it sometimes stays in parallel mode all the way down to around 80kph (50mph). While you'd think it would switch to series mode and rev up the engine because it's climbing, this is not always the case. Sometimes, it simply prefers to stay in parallel mode and consume battery to make up for the power that the ICE can't produce at that RPM.


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 Post subject: Re: So why do we have Hybrid Electric Vehicles.
PostPosted: Mon Jan 07, 2019 1:00 pm 
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Joined: Thu Feb 26, 2015 5:58 pm
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Location: Near Port Macquarie Australia
STS134 wrote:
I'm guessing that you never tried to do a run up the Grapevine on I-5 (6% grade for 5 miles straight) at 80+ mph. https://priuschat.com/threads/highway-m ... ls.124036/ People are reporting that it had trouble maintaining 60 mph with the accelerator floored once the batteries drained (post #20 and #21).


Ok, finally had a chance to read that discussion on priuschat. Yep, never gone up the Grapevine on I-5 (6% grade for 5 miles straight) at 80+ mph in a standard Prius let alone a Prius C which is what the discussion was about . Now from memory the Prius C had a smaller petrol motor and drive battery. Mine was the standard Gen 3 Prius.

Now could the standard Prius go up the Grapevine at the speed limit? Not sure.


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