GM: Chevy Volt Won't Be Labeled Zero-Emission - or 230 MPG
Thread Starter
Registered User
Joined: Dec 2002
Posts: 1,505
From: Charleston, WV
GM: Chevy Volt Won't Be Labeled Zero-Emission - or 230 MPG
Engineers leading development of General Motors Co.'s 2011 Chevrolet Volt extended-range Chevrolet Volt with 230 MPG sign - 168.JPGelectric vehicle through its final stages told reporters the car will be "right up there with (GM's) most emissions-efficient vehicles," but will not be certified by the Environmental Protection Agency as a zero-emissions vehicle, as are pure battery-powered vehicles.
Also: fuhgeddabout that 230 miles-per-gallon city-cycle fuel economy rating GM so controversially touted last summer. Although GM's Volt engineers aren't saying it won't happen, they said the number was based on a preliminary fuel-economy measure proposed by the EPA for vehicles like the Volt and that the actual fuel-economy rating methodology is still to be decided.
But listen between the lines and it's clear the 230-mpg claim - rumored to be hotly disapproved by Volt developers when the company and then-CEO Fritz Henderson gaily hyped it last August - almost certainly will not be supported by whatever test methodology finally determines the Volt's official fuel-economy number. The 230-mpg number was outsized because of the Volt's ability to travel relatively long distances without burning any gasoline.
Andrew Farah, chief engineer for the Volt and the variant for GM's Adam Opel AG European unit, the Opel Ampera, said the 230-mpg figure was based on GM's knowledge of the EPA's thinking in preliminary talks about the Volt.
Calculating the fuel economy of the Volt is a particularly difficult job, Peter J. Savagian, engineering director, hybrid powertrain systems engineering, told AutoObserver, because of the many variables involved with its "blended" strategy of electric and internal-combustion operation.
Also: fuhgeddabout that 230 miles-per-gallon city-cycle fuel economy rating GM so controversially touted last summer. Although GM's Volt engineers aren't saying it won't happen, they said the number was based on a preliminary fuel-economy measure proposed by the EPA for vehicles like the Volt and that the actual fuel-economy rating methodology is still to be decided.
But listen between the lines and it's clear the 230-mpg claim - rumored to be hotly disapproved by Volt developers when the company and then-CEO Fritz Henderson gaily hyped it last August - almost certainly will not be supported by whatever test methodology finally determines the Volt's official fuel-economy number. The 230-mpg number was outsized because of the Volt's ability to travel relatively long distances without burning any gasoline.
Andrew Farah, chief engineer for the Volt and the variant for GM's Adam Opel AG European unit, the Opel Ampera, said the 230-mpg figure was based on GM's knowledge of the EPA's thinking in preliminary talks about the Volt.
Calculating the fuel economy of the Volt is a particularly difficult job, Peter J. Savagian, engineering director, hybrid powertrain systems engineering, told AutoObserver, because of the many variables involved with its "blended" strategy of electric and internal-combustion operation.
Registered User
Joined: Sep 1998
Posts: 4,320
From: Memphis
I've been saying this from the very beginning. The EPA needs a new testing and rating standard for vehicles that are driven by electric motors.
City and highway range on a battery full charge without the gasoline motor kicking in.
and
Fuel efficiency once the battery is effectively depleted.
Making some goofy combined rating makes no sense since results will vary dramatically depending on driving conditions.
City and highway range on a battery full charge without the gasoline motor kicking in.
and
Fuel efficiency once the battery is effectively depleted.
Making some goofy combined rating makes no sense since results will vary dramatically depending on driving conditions.
Registered User
Joined: Nov 2000
Posts: 2,712
From: Ontario
You could see whatever method the EPA chooses playing a huge part in GM's powertrain control strategy. For example GM has mentioned that when the gas motor needs to kick on, it won't really charge the batteries so much as generate just enough electricity to move the car. As such, the engine speed will vary somewhat with the load, and the idea is to just get the car home where it can charge on the grid. But maybe it might be better to run the engine at a fixed speed where it is most efficient, produce more power than is immediately needed, and therefore charge the batteries a bit. Then kick off at a certain point, and repeat.
I'll bet the programming strategy on the Volt would be really fascinating to work on.
I'll bet the programming strategy on the Volt would be really fascinating to work on.
Registered User
Joined: Apr 2005
Posts: 824
From: North of Cincy
I've been saying this from the very beginning. The EPA needs a new testing and rating standard for vehicles that are driven by electric motors.
City and highway range on a battery full charge without the gasoline motor kicking in.
and
Fuel efficiency once the battery is effectively depleted.
Making some goofy combined rating makes no sense since results will vary dramatically depending on driving conditions.
City and highway range on a battery full charge without the gasoline motor kicking in.
and
Fuel efficiency once the battery is effectively depleted.
Making some goofy combined rating makes no sense since results will vary dramatically depending on driving conditions.
Registered User
Joined: Sep 2002
Posts: 9,705
From: Oakland, California
Vehicle range is more important that anything else. Tell me how far I can travel at 65 mph on a full battery charge + tank of fuel combined. That, plus price and other features would be the final determining factor for which plug-in hybrid I would purchase. 
Registered User
Joined: Mar 2003
Posts: 390
From: Huntsville, AL
Registered User
Joined: Aug 2000
Posts: 6,165
From: Sterling Heights, MI
I can see why it might be a bit confusing to rate MPG for a vehicle that has the potential to never use a drop of gasoline. The only fair way to do this is to tell us how many miles the vehicle can get, both in city and highway driving, on a full charge and full tank of gas and divide that number by the amount of fuel used, with some type of disclaimer about mileage widely varying depending on charging habits.
The biggest challenge GM faces with this car is marketing it and getting people to understand it. There are so many misconceptions about the car out there right now it's amazing....
Registered User
Joined: Jan 2000
Posts: 10,285
From: Albany, NY
Electric car should be measured in kW per mile
Plug-in hybrid should be measured 3 ways, First 20 miles (almost all electric), until a full charge and a full tank of gas are gone (whats the range when I leave my house in the morning), and 200-1000 miles (mostly gas only after initial charge is gone)
Plug-in hybrid should be measured 3 ways, First 20 miles (almost all electric), until a full charge and a full tank of gas are gone (whats the range when I leave my house in the morning), and 200-1000 miles (mostly gas only after initial charge is gone)
Registered User
Joined: Nov 2000
Posts: 16,176
From: Chicagoland IL
It will be interesting to see how this plays out. GM could really use an astronomical MPG rating for the Volt. It sure would help out with CAFE.
Maybe GM's majority owner has some pull with the EPA....
Maybe GM's majority owner has some pull with the EPA....
Ya think?
Registered User
Joined: Aug 2003
Posts: 915
From: Tucson, AZ
Impossible, not every power plant uses the same fuel source, and not all are even the same efficiency given the same fuel source. Then you would have to account for transmission losses as well to get a real number.