2011 Chevrolet Volt Verdict
With a Year Gone By, Its Time for Some Answers
At 26,861 miles and during the very last week of its stay with us, our long-term Chevrolet Volt's computerized maintenance warning finally illuminated: Time to change the oil. For the First Time. I'd been fretting about whether the remaining oil life display had gone haywire, and was actually headed for the dealer, anyway.
Of course, not all those miles had been gasoline-powered. And even then, the little 1.4-liter engine's workload was fairly low stress -- it doesn't do a lot of revving. Even so, I had an oil sample taken and sent it to Blackstone Laboratories for analysis.
Result? Traces of aluminum, copper, and particularly iron, were high. I sent the report on to GM for comment, and they replied that this was "within normal range." Blackstone's Andy Martin retorted, "Well, you can't go wrong following what's recommended, but..." Yes, if I had known this, I'd have changed it earlier, too.
So there we are. A final curiosity from the car I drove from Detroit to L.A. with my daughter riding shotgun, filled 66 times with gas, charged 271 times, and a thousand times politely answered questions like "aren't you worried you'll run out of electricity and stop?" and "afraid of it catching fire?" and "how much?" Now that the Volt's year with us is up, it's time for some answers.
I'll start with those three questions I've heard so often. When the battery was depleted, the engine always started seamlessly. The Volt doesn't "die" at the end of its EV range, as pundits have claimed. Nor did it ever erupt into a lithium-ion inferno. However, it's quite evident from the car's sales that it simply costs too much for most folks (a $32,495 base price even after the federal tax credit).
Still, the real headline here is that nothing ever went wrong the car. Zip. Zero. It was breathtakingly reliable, given that the Volt is (and try arguing this with me) the biggest quantum jump in automotive technology in decades. Spooky-advanced-tech cars like this, I've noticed, are actually frequently more robust than conventional cars because their engineers are playing it very, very safe, knowing that everybody's watching with magnifying glasses.
"GM made big claims for the Volt, and our example lived up to every one of them."
A close runner-up to that impressive reliability is the fact that the car operated exactly as Chevrolet claimed it would. Driven normally, our car usually traveled between 35 and 40 miles per charge (our average was 36.8; at worst, it was 24 miles; at best, 45). Our battery-depleted (gas-powered) mpg was 38.7 (the EPA says 37). Here, in Southern California, the Volt cost about 60 percent less to operate as an electric car than as a gas one.
Niggles? The car's very low air dam (a mere 3.5 inches above the pavement) is essentially a sacrificial flap expected to scrape and flex; and ours become rather ratty-looking, though I regarded the marring as proud battle scars in the name of aerodynamic efficiency. (Even now, I'm still braking for small dips out of habit; a 1.2-inch-shorter substitute is available.) Another footnote was that filling the car with gas was sometimes balky, with the dispenser frequently shutting off. I found that holding it in a lifted position solved the problem, but, of course, you have to stand there and hold it.
A parting thought? To all the skeptical "gotcha" observers and disreputable political talking heads, I'd like to remind you of the 2001 Toyota Prius. I well remember driving it. It was homely. Its regenerative brakes were soupy. It wasn't cheap. Many suspected that Toyota lost money on it, and its technology benefited from Japanese government support. It sold poorly.
Hmm, I just checked Prius (family) sales for April 2012, and guess what? It's in third place among all cars, behind the Camry and the Accord. My point is, we need a much bigger perspective here. The Volt's costs will come down. Efficiencies will be incrementally learned. Let's meet up again in 11 years and see how the 2023 Chevrolet Volt is doing then.
|Service life||12 mo/26,683 mi|
|Options||Audio system with nav package ($1995), Premium Trim Package ($1395: heated leather seats, leather steering wheel, door trim), rear camera and parking assist ($695), polished aluminum wheels ($595), Bose Premium speaker system ($495) Price as tested / $45,170 ($37,670 after federal tax credit)|
|Avg econ/CO2||47.6 equiv mpg/0.45 lb/mi|
|Maintenance cost||$126.36 (tire rotation, oil change)|
|3-year residual value*||$16,797|
|Recalls||Battery safety enhancements (not an official recall)|
|*Automotive Lease Guide|
Volt Charging and EV Range
Generally speaking, the more slowly you charge a battery, the more efficient the charging process, though the longer time it takes is equally inconvenient. So of the Volt's two charging rates -- Level 1 (standard 120-volt wall-plug power) and 240-volt Level 2 power -- the former should be more efficient. But in this car's case, it's not. And the reason is that the Volt's trickle charger -- which is in the cargo hold -- suffers enough resistance loss that Level 1 is worse than Level 2 charging.
On average, our Volt consumed 11.99 kW-hrs during Level 2 charging. During Level 1, it required 12.84, or 7 percent more. Remember, we're charging the same battery here, and the car's estimated range was essentially the same after charging both ways. So that higher Level 1 number simply reflects its greater losses.
If you look at the nearby graph, you'll notice that in addition, there was a greater variation in the energy needed for Level 1 recharging. To paraphrase Mike Duoba of Argonne National Laboratory, a battery should be thought of as a rubber gas tank for electricity -- sometimes it holds more and sometimes less. It depends on the circumstances. I can't say that I know for sure why we saw greater variations while Level 1 charging, but ambient temperature affects the charging rate and our Level 1 charging was usually done outdoors.
The all-electric range shown on the techy instrument screen proved eerily accurate. Reviewing our trips where its fully charged battery was exhausted, the Volt's actual EV range averaged to be just 0.9 mile less than what was predicted. In the nearby graph you can see that the data points are slightly scattered, and this is largely because some of the trips were driven especially fast, and others benefitted from lots of stop-and-go driving. But when driven in a consistent manner on the same roads over distances beyond its EV range, the car would quite often start its engine on the very same city block, on every trip. The other graph is a distribution of our gas-equivalent EV mpg for every all-EV trip we took, sorted from worst to best.
"Burn" is a word you don't want to mention around EVs, but in the Volt's case, something actually did get singed. The "convenience" trickle charger's three-point prong didn't last long under constant use, and eventually became heat-damaged.
And here's where I need to admit to making a mistake in an earlier Volt update. In order to collect data about how much energy the Volt was being charged with, we had an EKM meter installed in our garage next to our AeroVironment 240-volt charger, and also bought a common energy meter (used for monitoring the efficiency of computers or microwaves) to collect its equivalent information during 120-volt charging. (When possible, we also gathered the number of kW-hrs added at ChargePoint stations).
Well, eventually we started to notice heat damage to the Volt's 120 trickle-charger plug and the meter's receptacle -- and I presumed the meter was to blame. The meter was replaced but the gradually worsening damage to the plug continued, until it was plain that the charger needed replacing as well.
That cost $475, and I confessed to the service manager that I believed it was our meter's fault. And to my chagrin, that meant the new charger wasn't covered by the warranty.
Subsequently, it's arisen that some Volt owners have been experiencing the same thing and recently GM has announced a "customer satisfaction program" (not a recall) to replace these chargers free of charge with ones with beefed-up cords when an owner brings a Volt in for the battery reinforcements.
Which leaves me with two thoughts. One, I have to believe that at least a few GM folks read my inaccurate update and didn't say anything. And two, ah, about that $475...
The Volt's carbon footprint while in EV-mode depends on where you live, as CO2 emissions from electrical generation swing wildly between states. In California, fully charging the Volt's battery has the CO2 impact of burning a half-gallon of gas; in Michigan, it's 1.1 gallons. This rather significant variability was recently addressed by the Union of Concerned Scientists, who noted that 45% of the American population resides in areas where EV-caused CO2 emissions (due to electrical generation) are lower than those produced by even very good (50 mpg) hybrids -- and in some areas, spectacularly so. Of course, the flip side is that there are other portions of the country where EVs can be beaten by very high-mileage conventional gas cars. Please peruse the nearby chart showing a comparison of the Volt's pounds of CO2 produced per mile when it's in either gas or EV mode, for every single state.
|State||EV CO2 lb/mi||Gasoline CO2 lb/mi|
|*Bold = less CO2|
|2011 Chevrolet Volt|
|Drivetrain layout||Front engine, FWD|
|Engine type||I-4, iron block/aluminum head, plus AC electric motors|
|Valvetrain||DOHC, 4 valves/cyl|
|Displacement||85.3 cu in/1398 cc|
|Battery type||16-kW-hr lithium-ion|
|Power (SAE net)||84 (gas)/149 + 72 (elec)/149 (comb) hp|
|Torque (SAE net)||92 (gas-est)/273 (elec)/ 273 (comb) lb-ft|
|Redline||N/A (4800 rpm max)|
|Weight to power||25.3 lb/hp|
|Transmission||Cont variable auto|
|Axle/final-drive ratios||2.16:1/7.01:1 (hwy speeds, N/A below)|
|Suspension, front; rear||Struts, coil springs, anti-roll bar; torsion beam, coil springs|
|Brakes, f;r||11.8-in vented disc + regen; 11.5-in vented disc, ABS|
|Wheels||7.0 x 17-in, forged aluminum|
Assurance Fuel Max
|Track, f/r||61.2/62.1 in|
|Length x width x height||177.1 x 70.4 x 56.3 in|
|Turning circle||36.0 ft|
|Curb weight||3767 lb|
|Weight dist, f/r||61/39%|
|Headroom, f/m||37.8/36.0 in|
|Legroom, f/m||42.0/34.1 in|
|Shoulder room, f/r||56.5/53.9 in|
|Cargo volume||10.6 cu ft|
|Acceleration to mph|
|Passing, 45-65 mph||4.8|
|Quarter mile||16.9 sec @ 84.3 mph|
|Braking, 60-0 mph||112 ft|
|Lateral acceleration||0.82 g (avg)|
|MT figure eight||28.1 sec @ 0.59 g (avg)|
|Airbags||Dual front, front side, f/r curtain|
|Basic warranty||3 yrs/36,000 mi|
|warranty, eng; battery||5; 8 yrs/100,000 mi|
|Roadside assistance||5 yrs/100,000 mi|
|Fuel capacity||9.3 gal|
|EPA city/hwy/comb econ||35/40/37 mpg; 95/90/93 mpg-e*|
|Energy cons, city/hwy||96/84; 35/37 kW-hrs/ 100 mi*|
|CO2 emissions||0.52; 0.00 lb/mi (at car)*|
|Recommended fuel||Unleaded premium or 110- or 220-volt electricity|
|*On gasoline; pure EV mode|