The Chevy Volt is in a class of its own compared to other plug-in hybrid electric vehicles (PHEVs). The Volt emits significantly less smog-forming pollution than other PHEVs, according to a GM study presented to the Society of Automotive Engineers. Furthermore, GM-Volt reports that the engineering analysis for the new 2016 Volt that will be on the market soon shows Chevrolet’s new Volt will outperform the 2011–2014 specification Volts studied.
GM-Volt explains the study and reasons the improvement is the Volt has a battery 2 to 4 times larger — rated at least double the all-electric range of any conventional plug-in hybrid. Thus, in this remarkable system architecture, even with a higher top battery-electric speed, the engine stays off longer. The Volt’s routine trips every day are thus cleaner.
The paper, “Chevrolet Volt Electric Utilization,” by A. Duhon, K. Sevel, S. Tarnowsky, and P. Savagian, reports that the Volt can offer 40 times or more all-electric trips compared to “competitors.” With such distinction, the Volt stands out far in front compared to PHEVs by Toyota, Honda, and Ford — which have batteries ½ to ¼ the Volt’s size.
The study focuses on the Volt’s primary strength: the Volt’s powertrain, and the decidedly solid efficiency in daily trips that results. GM-Volt explains: the study cites “SAE precedent to justify its assertions, the paper distinguishes between an ‘extended-range electric vehicle ‘(‘E-REV’) and generic ‘plug-in hybrid electric vehicle’ (PHEV).” In the past few years, critiques point to the “E-REV” as a marketing ploy by GM, but the SAE offers separate definitions for each:
E-REV: “A vehicle that functions as full-performance battery electric vehicle when energy is available from an onboard RESS [rechargeable energy storage system] and having an auxiliary energy supply that is only engaged when the RESS energy is not available.”
PHEV: “A hybrid vehicle with the ability to store and use off-board electrical energy in the RESS.”
Thus, considering the Volt uses two power sources, it can be defined also as a plug-in hybrid, GM-Volt points out, but “the SAE makes a finer distinction in how the car actually functions next to other competitive PHEVs.”
This real-world data, collated anonymously, is from more than 60,000 2011–2014 Volts analyzed in the study. The data is via GM’s OnStar telematics service engaging owners from October 2013 through September 2014. Thus, all four seasons were interpreted. The study’s other data samples include 621 vehicles monitored by the Southern California Association of Governments, as well as data from the National Renewable Energy Lab, Idaho National Laboratory, and more (for the other PHEVs).
The Volt is an EV with gas backup, running gas-free exceptionally more than other PHEVs. GM-Volt continues:
The study found “trip initial engine starts” for the generation-one Volts were reduced by 70 percent compared to conventional vehicles under the same conditions:
By comparison, also, the paper observed “a PHEV’s lack of full-performance all-electric capability results in engine operation under everyday speed and/or load conditions, regardless of available battery energy.”
“The dominant factor in EV trip capability of a PHEV is determined to be the amount of power available from the battery or electric motor before an engine start is required,” continued the paper. “With full vehicle performance capability as an EV, a 35 mile E-REV is found to provide up to 40-times more all-electric trips than a PHEV over the same data set.”
A “35-mile E-REV” would be none other than 2011-2012 Volts. The 2013 and 2014 Volt models increased to 38 miles rated range with an increase from 16.0 kilowatt-hours for 2011-2012s to 16.5 kilowatt-hours for 2013-2014s. Not studied were 2015s which have 17.1-kwh batteries.
Expectations are that the 2016 Volt will be even more superior: “Based on the first-generation Volt’s ‘ in-use operating data,’ the paper projects the second-generation Volt will be able to complete 80 percent of total miles driven using electricity.”
Anticipated is a 25% improvement further than first-generation Volts with similar driving and charging styles studied. “The paper points out the 2016 Volt is rated 50 miles EV range and 41 mpg compared to 38 miles and 37 on premium for the 2013-2015 Volt.”
As far as air pollution, the paper analysis shows that EPA Plug-in Hybrid Electric Vehicle labels with a numerical smog score from 1 to 10 meant to grade degree of smog-forming emissions have an outcome of being “less clear for the consumer.”
“This rating may vary by state, and typically reflects the smog-forming emissions of the base engine without regard for the all-electric capability,” says the paper.
The paper adds, “States that modify the label smog score for advanced technology vehicles will change the rating based on a PZEV or AT-PZEV certification, which requires SULEV engine exhaust emissions as a first pre-requisite. Existing smog score label methodology does not reflect the infrequent engine starts on an EREV vehicle.”
The substance of the paper is that the Chevrolet Volt surpasses other PHEVs… by far. As EV Obsession reminds us, the Chevy Volt was the most loved car in the United States for two years in a row before the Model S came along, based on surveys of owner conducted by Consumer Reports. It also landed “Best Green Car 2015″ on Consumer Reports Top 10 List. Surely, this is due to the combination of two factors that no other electrified vehicle has offered to date: a quite useful all-electric range, and a gas extender that lets you get along as if in a conventional car of the battery runs out of juice.
If you want some more details of the coming 2016 Volt, Gas2 has more on the energy-saving, emissions-reducing car with a walkaround that reveals key hidden improvements. Customer feedback drove some changes, such as a lighted charging port, which remedies charging a Volt in the dark and offers feedback on the charging status.