Pure BEV Dogma

[qwk]

Sure. But it still contains the word "hybrid" so still confusing to some.



Yes I know you do. You are a wealth of knowledge and I enjoy reading your perspective on all things EV. But you may not have an understanding of how they "feel" to drive them. And the Volt "feels" like an EV.

To be fair, the Prius also feels like an EV, when the ICE is off for brief periods of time.

 

[Doug_G]

Agree. It's confusing to deny that the Volt is a hybrid but it's clarifying to describe it as a kind of hybrid that follows an EREV operating strategy -- first it's a BEV and then it's a conventional hybrid.

Easier to simply explain that rather than spewing out acronyms and jargon.

I think an important component of that conversation is the discussion of when and why the gas engine starts up.

That's only really worth getting into if the individual in question is asking for the information. Generally speaking I am more comfortable giving a recommendation on a specific car model, rather than the technology it contains. If they want to ask why I would prefer one over the other, then I can give more detail.

 

[JRP3]

Sure. But it still contains the word "hybrid" so still confusing to some.



Yes I know you do. You are a wealth of knowledge and I enjoy reading your perspective on all things EV. But you may not have an understanding of how they "feel" to drive them. And the Volt "feels" like an EV.

My point is the way a vehicle "feels" is not really the issue, nor is how it's used, it's the way it's designed and built. Basically the Volt shares all the same components with a conventional Prius hybrid, just sized differently, which allows different performance parameters in various modes. For whatever reasons Volt owners seem to want to deny the clear design connection the car shares with conventional hybrids while trying to create a connection with EV's that it does not share. An EV does not contain half or more of the components and the complexity of a hybrid, simplicity is a large benefit of EV design. No hybrid can claim simplicity of design and construction.

Since we all acknowledge that there will be some confusion when introducing new technology to the general public it seems worth considering what sort of confusion may be more detrimental. Volt owners claim that people think their car is like a Prius. As I pointed out in many ways it is, but let's look at the ramifications of that comparison. Generally the Prius is known to be a very efficient and popular vehicle. If the Volt is seen as a better Prius that's really not so bad. On the other hand a number of us have described our experiences and shown media examples where people think the Volt is a $40,000 EV with only 40 miles of range or less that can run out of charge and leave you stranded. That's a really bad comparison, basically if that were what the Volt really was almost no one would buy it. It makes the Volt look bad, and it makes EV's look bad. I suggest that the Prius comparison is the more benign "error", and easily corrected. Don't be concerned if your vehicle is confused with one of the most efficient vehicles ever built. Do be concerned if it's seen as an over priced short range EV.

 

[dpeilow]

A haha hahaha.

Is this still going on?

 

[Doug_G]

LOL yeah, they somehow even managed to suck me back in...

 

[Duckjybe]

...For whatever reasons Volt owners seem to want to deny the clear design connection the car shares with conventional hybrids while trying to create a connection with EV's that it does not share.

I am not denying it doesn't have a hybrid design connection, but it certainly does have an EV connection?!!

I will continue to describe the Volt to people as "Electric with gas backup", which I think is perfectly descriptive.

LOL yeah, they somehow even managed to suck me back in...

I blame you and Mike for sucking me in - even though I know that sparring with JRP3 is a futile affair, just ask John Petersen. I'm out.:smile:

 

[Lanny]

Photo taken of Chevy Volt on display at the 2012 Washington Auto Show. GM said it, not me.

 

[JRP3]

Now you've done it, heads are going to explode :biggrin:

 

[qwk]

An EV does not contain half or more of the components and the complexity of a hybrid, simplicity is a large benefit of EV design. No hybrid can claim simplicity of design and construction.

This is a key point. EV's are simple creatures, ICE not so much, and hybrids are even more complicated than ICE vehicles.

 

[DuncanWatson]

One of the things that I tell my wife about why I want an (B)EV is the savings in maintenance and simplicity of design. That just isn't something you get in a hybrid or plugin hybrid. They do have some savings due to much fewer oil changes but there is a lot of complexity, moving parts and fluids that still demand care and feeding.

 

[liuping]

One of the things that I tell my wife about why I want an (B)EV is the savings in maintenance and simplicity of design. That just isn't something you get in a hybrid or plugin hybrid. They do have some savings due to much fewer oil changes but there is a lot of complexity, moving parts and fluids that still demand care and feeding.

The ICE on a Volt may require much less maintenance than the ICE in a normal car or hybrid, if most of your driving is in EV mode.

So far we have over 25,000 miles on our volt, but just 2700 using gas. So the ICE only needs the maintenance of a car with 2500 miles, i.e. basically nothing. Not even an oil change in over 25,000 miles of driving.

 

[Jeff N]

So far we have over 25,000 miles on our volt, but just 2700 using gas. So the ICE only needs the maintenance of a car with 2500 miles, i.e. basically nothing. Not even an oil change in over 25,000 miles of driving.

My Volt (VIN #42) is just over 3 years old with 69,228 miles (65% on battery charge). Following GM recommended maintenance, it's had a single oil & filter change and no other ICE-specific maintenance. Next oil change is due a year from now when it will likely have over 85,000 miles. I think I've spent less than $50 on maintenance and repairs.

 

[dpeilow]

I'm over 24,000 miles and 71% oil life remaining.

 

[brianman]

@Doug_G, @jerry33
Perhaps we should simplify the terminology even further.

Engine -- Yes. Term: Sucks.

 

[rolosrevenge]

So far we have over 25,000 miles on our volt, but just 2700 using gas.

You used a meaningful metric when describing your usage with the Volt rather than mpg :love: Thank you!

 

[stopcrazypp]

Nothing in GM's SAE paper that you linked to states any requirements about EREV behavior after the battery runs out of grid charge and the engine starts up. This EREV requirement of yours does not come from GM or this SAE paper that you link to.

I'm basing it on this definition as a direct quote from the paper (p4):

A vehicle that functions as a full-performance battery electric vehicle when energy is available from an onboard RESS and having an auxiliary energy supply that is only engaged when the RESS energy is not available.

Actually what you quoted makes it quite clear:

As a full-performance battery electric vehicle, the battery, motor, and power electronics must be sized for the full capability of the vehicle.

This makes it pretty clear my interpretation is correct. It's not comparing EV vs CS mode, it's saying that in EV mode you get the full capability (0-60/top speed) in reference to the car itself as a whole (all modes). If a car gets a slower 0-60/top speed in EV mode that means there is at least one part of those three components that's not sized for the "full capability". In the case of the ELR and Fisker, it's the battery (doesn't deliver enough power on its own to give the full performance without the ICE kicking in, exactly the same reason why the Prius needs the ICE on for acceleration even though the motors can provide enough power). I don't see how your interpretation (that it's based on performance of other cars in its class), makes any sense in engineering, as whether a vehicle is "competitive" in its class is going to vary depend on which class you consider and how strict you are (for example the Energi gets 85mph top speed and 0-60 in 15 seconds in EV mode, so does it qualify as an EREV?).

And on the subject of starting the ICE, the paper also says:

An EREV does not start the engine until all useable on-board electrical energy has been used.

The i3 REx doesn't allow the user to start the ICE until the battery is depleted. In the Volt, the user can start the ICE using mountain or hold mode. I'm pretty sure mountain/hold mode came after this paper. This is aside from maintenance needs (which you say may be necessary for all PHEVs).

As for the point about series PHEV. That was how the Volt was advertised as a concept and up until 2010 (when it was revealed that it's a series-parallel) that's what most people referred to it as (and some still do today).

- - - Updated - - -

As for those arguing that EREV is less confusing than PHEV, are you advocating we call all PHEVs, EREVs? Because so far, EREV is an additional term on top of PHEV, not really a replacement term.

I think PHEV is actually quite simple to explain to a general audience, it's a car that can use both gasoline (the "hybrid" part) and electricity from the grid ("plug-in" part). Trying to explain the difference between EREV and PHEV is a lot more difficult (as you can see even in this thread, we don't have an agreement over this, much less when talking with a more general audience).

 

[rolosrevenge]

True story, I told my wife that we should look into leasing a Volt. She asked what type of car it was. I said a Plugin Hybrid that can go for 40 miles on only electricity. She said, "I like hybrids". If I had said it's an extended range electric vehicle she would have had no idea what that means.

 

[Jeff N]

I'm basing it on this definition as a direct quote from the paper (p4):

A vehicle that functions as a full-performance battery electric vehicle when energy is available from an onboard RESS and having an auxiliary energy supply that is only engaged when the RESS energy is not available.

As I said recently, after reading the paper again I think the "full-performance" part of that is just descriptive and not part of the normative definition.

Actually what you quoted makes it quite clear:

As a full-performance battery electric vehicle, the battery, motor, and power electronics must be sized for the full capability of the vehicle.

This makes it pretty clear my interpretation is correct. It's not comparing EV vs CS mode, it's saying that in EV mode you get the full capability (0-60/top speed) in reference to the car itself as a whole (all modes). If a car gets a slower 0-60/top speed in EV mode that means there is at least one part of those three components that's not sized for the "full capability". In the case of the ELR and Fisker, it's the battery (doesn't deliver enough power on its own to give the full performance without the ICE kicking in, exactly the same reason why the Prius needs the ICE on for acceleration even though the motors can provide enough power).

So "It's not comparing EV vs CS mode" but actually it really is? That seems like an incoherent argument.

I'm not sure about the Fisker, but the ICE does not kick in on the ELR unless the battery is empty and the vehicle has already switched over to hybrid mode (same as Volt). What some people are complaining about is that the ELR goes 0-60 mph faster in hybrid mode than it does in EV mode. The Volt is about the same in both modes going 0-60 mph but diverges at 0-70 and from 45-65.

I showed a table of 0-100 mph performance values of the Volt in battery-only vs. hybrid mode taken from a MotorTrend article. That data demonstrated that the Volt is also faster in hybrid mode much like the ELR. Do you really think the GM engineers who wrote this paper (and were working on the Volt program) meant to define EREV in a way that excluded the Volt?

I don't see how your interpretation (that it's based on performance of other cars in its class), makes any sense in engineering, as whether a vehicle is "competitive" in its class is going to vary depend on which class you consider and how strict you are (for example the Energi gets 85mph top speed and 0-60 in 15 seconds in EV mode, so does it qualify as an EREV?).

Again, I don't think "full-performance" is really part of their normative definition of EREV any more than the battery packaging is.

For example, in the same paragraph you are quoting from they say:

The vehicle must also be architected to allow packaging of the large EREV battery which has a greater size due to the full EV requirement.

But earlier the say:

An EREV is typically also architected to accommodate packaging of these systems while retaining performance and utility.

I think the core normative definition is that a vehicle operating on an EREV strategy:

...does not need to start the engine for speed or power demands from the driver...

They were a little loose in what was normative and what was merely descriptive.

For what it's worth, I think most people would agree that the Volt is in the same competitive class as the LEAF and Prius. I could post a table from another MotorTrend article comparing performance between those 3 cars at speeds between 0-100 mph with the Volt in battery-only mode. In summary, all 3 were about the same from 0-40 mph and then the Volt performed better at the higher speeds.

By the way, why would it make "any sense in engineering" to artificially limit the performance of the hybrid mode in the Volt or ELR so that it performs no faster than the battery limitations of the EV mode? Why would anyone do that other than other than to satisfy irrational EV purity demands?

I've already said that I think the Ford Energi's optional "EV now" mode would quality as an EREV operating strategy if Ford made it the default when you start the car. They chose not to because they knew its performance was not fully competitive.

The key difference between ordinary PHEV and EREV is whether the engine will start up when the driver stomps the accelerator or drives up steep hills at full speed.

And on the subject of starting the ICE, the paper also says:

An EREV does not start the engine until all useable on-board electrical energy has been used.

The i3 REx doesn't allow the user to start the ICE until the battery is depleted. In the Volt, the user can start the ICE using mountain or hold mode. I'm pretty sure mountain/hold mode came after this paper. This is aside from maintenance needs (which you say may be necessary for all PHEVs).

I don't think they meant to preclude the driver from intentionally overriding the default strategy of the car. Why would they want to do that? They meant that the driver could not inadvertantly start the engine by accidentally pushing the accelerator too hard.

In any case, the European version of the i3 with the range extender does allow the driver to intentionally request the starting of the engine, according to usually reliable bloggers. The US version does not allow this, apparently in order to be in compliance with certain CARB regulations.

As for the point about series PHEV. That was how the Volt was advertised as a concept and up until 2010 (when it was revealed that it's a series-parallel) that's what most people referred to it as (and some still do today).

So?

You earlier said:

Originally GM's definition was much simpler: EREV = series PHEV, but they couldn't use that definition after they changed the Volt's design.

You still haven't offered any evidence in support of that claim.

As for those arguing that EREV is less confusing than PHEV, are you advocating we call all PHEVs, EREVs? Because so far, EREV is an additional term on top of PHEV, not really a replacement term.

Certainly not.

I'm arguing that GM's notion of EREV conveys a useful and important characteristic. It says that if you stomp on the accelerator or climb a steep road at the highest speed the car can go in its default operating mode that it will not start the engine unless the battery is "empty".

A non-EREV plugin hybrid would start the engine in those circumstances in order to supply additional power.

 

[JRP3]

I'm arguing that GM's notion of EREV conveys a useful and important characteristic. It says that if you stomp on the accelerator or climb a steep road at the highest speed the car can go in its default operating mode that it will not start the engine unless the battery is "empty". It's up to consumers to decide if the car has adequate performance.

So you are hinging the entire argument on a specific condition that is extremely rare and only lasts an extremely short time period the few times it may actually happen. And you think this distinction carries great weight and requires a completely new vehicle classification.

 

[dsm363]

Does all of this really matter? It's basically

Does it have a plug? Yes or no

How far can I go on EV mode without using gas?

That pretty much satisfies most normal people's interest level. The rest is mostly academic.