My first thought: Sure, that is a good description of the Chevrolet Volt
My second thought: McLaren P1 and Porsche 918
I am going with my *second* thought. :smile:
GSP
-
Want to remove ads? Register an account and login to see fewer ads, and become a Supporting Member to remove almost all ads.
Pure BEV Dogma
- Thread starter bonnie
- Start date
My first thought: Sure, that is a good description of the Chevrolet Volt
My second thought: McLaren P1 and Porsche 918
I am going with my *second* thought. :smile:
GSP
I thought the definition of the '40' implied range on EV mode only. I don't believe the PIP has a designated EV range as if you accelerate too quickly the gas engine takes over. I may have that wrong though.
Are there PHEVs with a X mileage designation that don't have full power under EV mode?
Yes. Every one of them, except for the Volt and the i3. Even GM's ELR does not have full power in EV mode.
The window sticker for PHEVs lists "all electric range" which is the distance the car can travel *on the EPA cycle* before the power required by the cycle starts up the gas engine. This is something like 7 miles for the PiP, and (count them) *zero* miles for the i8.
There also is a "gas+electric range" on the sticker, which is the distance before the battery hits minimum SOC and all energy comes from gas in a "conventional hybrid" mode (CS mode). This is about 15 miles for the PiP and the i8.
GSP
Pip has an AER of 6 (because the engineturns on in a rapid acceleration test). Its ble ded range is 11 miles, using 0.002gal per mile and 0.29kWh/mi. You can think of it as about 1 mile at 45.45mpg and 10 miles at 0.319kWh/mi.
The Volt can accelerate a bit faster 0 to 60 when its running the engine. So really, yes, you do get a bit more power if the engine's running, but it's not really severely limited like the PiP or Energis, so I wouldn't call that a "can't be an EREV" issue. Fact is that if you get in a Volt or ELR shift into gear and press go down to the floor, it'll accelerate in reasonable time upto the car's max. My gripe is that having to run the engine for supplementary heat below 15F isn't good enough for an EREV.
Last edited:
Gee, I thought we had this all figured out by now. 
The recurring pattern I see in these discussions is the refusal to consider more than one concept at a time.
"It's an EV!"
"No, it's a hybrid!"
"No, it's an EREV!"
"No, it has a parallel drive mode!"
People, please... It's an EREV or extended range electric vehicle meaning, by GM's actual sensible definition, it does not start the gas engine due to torque demand or vehicle speed and it is capable of full-power driving on the highway according to a definition specified by the California Air Resources Board.
Therefore it is both an EV and a PHEV. It is a PHEV because it runs on both gasoline and grid-sourced stored battery power at various times. It is a HEV (hybrid) because a PHEV is a subtype of HEV.
The concepts of EREV and series vs series/parallel hybrid have nothing whatever to do with each other. EREV says nothing about what happens after the range extender starts supplying power.
EREV is a usefully descriptive concept because a significant number of customers want to know if mashing the "go pedal" will cause the gas engine to start burning fuel when the battery still has usable power.
Is the Volt an EREV by that definition? Yes.
Is the ELR an EREV by that definition? Yes.
Is the i3 an EREV by that definition? Yes.
Is the i8 an EREV by that definition? No.
Is the Ford CMAX or Fusion Energi an EREV by that definition? Yes, but only if placed in EVNow mode.
Is the Prius Plugin an EREV by that definition? No.
Some people object to this definition of EREV because it allows the gas engine to start under winter cold climate conditions to assist in cabin heating. Volvo has considered building an "EV" with a hydrocarbon-powered cabin heater. Would this still be considered an EV? I say yes.
The recurring pattern I see in these discussions is the refusal to consider more than one concept at a time.
"It's an EV!"
"No, it's a hybrid!"
"No, it's an EREV!"
"No, it has a parallel drive mode!"
People, please... It's an EREV or extended range electric vehicle meaning, by GM's actual sensible definition, it does not start the gas engine due to torque demand or vehicle speed and it is capable of full-power driving on the highway according to a definition specified by the California Air Resources Board.
Therefore it is both an EV and a PHEV. It is a PHEV because it runs on both gasoline and grid-sourced stored battery power at various times. It is a HEV (hybrid) because a PHEV is a subtype of HEV.
The concepts of EREV and series vs series/parallel hybrid have nothing whatever to do with each other. EREV says nothing about what happens after the range extender starts supplying power.
EREV is a usefully descriptive concept because a significant number of customers want to know if mashing the "go pedal" will cause the gas engine to start burning fuel when the battery still has usable power.
Is the Volt an EREV by that definition? Yes.
Is the ELR an EREV by that definition? Yes.
Is the i3 an EREV by that definition? Yes.
Is the i8 an EREV by that definition? No.
Is the Ford CMAX or Fusion Energi an EREV by that definition? Yes, but only if placed in EVNow mode.
Is the Prius Plugin an EREV by that definition? No.
Some people object to this definition of EREV because it allows the gas engine to start under winter cold climate conditions to assist in cabin heating. Volvo has considered building an "EV" with a hydrocarbon-powered cabin heater. Would this still be considered an EV? I say yes.
Last edited:
rolosrevenge
Dr. EVS
So long before GM thought they had come up with some new and innovative concept (they didn't) there were these things called trains. Diesel trains in the US use their engines to drive electric motors which drive the wheels. If you put a battery in between there, you don't suddenly have an extended range electric train, you have something called a series hybrid. Series hybrid drive-trains have existed for a long time, though not in passenger cars. If you add a plug to it, you have what the Volt has, which is is Plug-in Hybrid drive-train. The only reason they started making up terms was that they needed a bailout from the US government, and they weren't very popular at the time and EVs were the in thing. But they didn't want an EV but they wanted my money (and yours and everyone in the US's) to save them. So they made up the term, much to the chagrin of engineers who knew all about hybrids and their various classifications. You too can read about the definitions of hybrids. Here's some links to start:
http://en.wikipedia.org/wiki/Hybrid_vehicle
http://en.wikipedia.org/wiki/Chevy_volt
After you've read them. Follow their citations to be properly educated.
http://en.wikipedia.org/wiki/Hybrid_vehicle
http://en.wikipedia.org/wiki/Chevy_volt
After you've read them. Follow their citations to be properly educated.
stopcrazypp
Well-Known Member
The whole Volt program was made in response to the film "Who Killed the Electric Car" where GM was the main one on the receiving end of the backlash. Plus it was when the Roadster came out and proved to the world that EVs were viable (the other factor was that GM's big fuel cell project at the time was a miserable failure and never did meet its promises).
GM still didn't want to admit it was possible to build a successful EV, so they went with the "range extender" idea, which allowed them to say that they weren't wrong to kill the EV1 while at the same time saying they were making an "electric car" to quell the backlash.
Last edited:
JRP3
Hyperactive Member
Take a conventional Prius, increase the size of the battery and add a plug, change the software so the ICE doesn't come on under hard acceleration until the pack is depleted, make no other structural or mechanical changes, and suddenly it fits your definition of EREV. Of course just calling it an EREV would not tell anyone how poor the performance would be in "EREV" mode. It's a nonsensical marketing term created by GM to confuse. In that they were quite successful.
There are cars driven solely by gas engines. These are ICE's.
There are cars driven solely by batteries. These are BEV's.
There are cars driven by some mix of the two. These are Hybrids.
The Volt is a hybrid. It has some different modes of operation. Nonetheless it combines two distinct power sources to provide locomotive force.
It's a fine car. Don't confuse not buying in to what feels like a "marketecture" term from the company with criticism of the platform.
I'd probably call it an EV, but I wouldn't consider it an EREV. GM might want to talk about power, but if you're burning fuel because the battery can't provide necessary power for everything that I'd consider to be normal operation they've made an engineering compromise on the EV side, and the engine's not just a range extender. For the Volt the result is that on my wife's whopping 6 mile round trip commute it'll run a cold engine in the cold on most average or colder winter mornings*. If anyone asks me about the Volt I refer to it as a "full performance plug-in hybrid". (I get why GM insisted on EREV over PHEV, but their (lack of) marketing has sown confusion.)
* Average winter low here is below 15F from December 18th to March 3rd.
Thanks for posting the accurate numbers for the PiP.
However, the Volt acceleration is matched in Charge Depleting vs. Charge Sustaining mode as closely as possible. Is it the same to the nanosecond? No, but nothing in the real world is.
Unfortunately, GM did not do this for the ELR. A big mistake in my book. None of the other PHEVs can do this, only the Volt and i3. (Although the i3 probably cannot match EV performance in CS mode)
GSP
PS. I agree about ERDTT (engine running due to temperature). A big annoyance about the Volt and totally unnecessary. I can't stand it and plan to modify my ambient temperature sensor before winter comes.
A BEVx is an EREV is a PHEV is an HEV. I don't mind trying to differentiate the Volt from other PHEVs in the naming, because they do not have the same performance characteristics. It's really inconsistent to be picky about not calling something one thing, but then reject attempts to refine the naming so that it does succinctly describe the characteristics. PHEV says nothing about how and when the car will use the engine, yet that's an extremely important characteristic for a plug-in. GM marketected EREV because they wanted to avoid the H word and emphasize the EV. I disagree with EREV because of the temperature issue, and since I'm not paranoid about hybrids I'd simply add an F for "Full" and call it an FPHEV.
You say "confuse", others might say "brand differentiation". Me, I don't care, and I don't think I'll ever bother reading this thread again. Nothing ever changes.
JRP3
Hyperactive Member
I'd say this thread has plenty of evidence of confusion regarding the Volt. Talking to the general public about the Volt also reveals much confusion about the vehicle.
Nope.
GM's SAE technical paper definition of EREV requires that the gas engine not start due to speed. It also requires an EREV to operate in EV mode as a full-performance electric vehicle (as defined by a CARB document) meaning that it is a highway capable car. Because the Prius has the engine permanently connected to the planetary carriers, the smaller motor/generator on the Sun gear has to spin when the Prius is operating only on the larger electric motor on the ring gear in order to keep the engine still. As the vehicle speeds up this smaller motor has to spin faster but it has a maximum design rpm of 10,000. At some point around 40-60 mph (it differs in different Toyota models) the engine starts up in order to prevent the smaller motor from exceeding this limit before it is damaged. The Volt avoids this problem by un-clutching the engine from the planetary gears when it operates in EV mode. The Prius has no clutches.
Because it would be severely limited in its highway speed capabilities, the modified Prius that you describe would likely not be considered to fit CARB's definition of a full-performance highway vehicle. Therefore it would not fit the definition of an EREV.
The present generation Prius would also be limited by its 80 HP electric motor but even more so by its DC-to-DC voltage converter. The Prius battery is a little more than 200V but the motors are designed to run at up to around 500 volts via a voltage converter that is design-limited to 38 kW. A battery-only Prius would therefore be limited to 38 kW or 50 HP and that also might violate the CARB definition. There have been 50 HP gasoline cars (like ancient VW bugs) but they were much lighter than the Prius you are describing. It would be adequate for maintaining speed but acceleration would be quite limited at 50-60 mph.
Last edited:
A battery-only Volvo with an ethanol cabin heater would be an EV, but a Volt that uses gasoline to assist in cabin heating at temperatures under 15F would not be an "extended range" EV. That seems like a severe distinction.
- - - Updated - - -
So you think GM should have artificially limited the performance when the gas engine is running?
JRP3
Hyperactive Member
Don't you think it's reasonable to consider the mode of propulsion, but not climate control? If I put a wood stove in my EV for heat it's still an EV because the propulsion is electric only, and can only be electric.
Similar threads
