We've all been bombarded with myriad technical descriptions of the Volt's plug-in hybrid powertrain. Heck, I've burned a lot of calories on analyzing the Voltiness of the Volt myself.
In the process, precious little discussion has focused on the rest of it. Our own track testing reveals that while it's no barn-burner, the Volt does ride and handle admirably for a four-door family/commuter sedan/hatchback thingy.
But does this somewhat expensive and technically interesting candidate for Car of the Year winner ride on a similarly advanced suspension? We pulled the wheels off to find out.
Up front, the Volt is pure MacPherson strut.
Mass reduction is always a priority when you add the weight of batteries to a car, but it is particularly nice to see mass reductions of the unsprung kind. And here we have it -- both the lower control arm (yellow) and the knuckle (green) are made of aluminum.
A reinforced plastic stabilizer link (green) trims a bit more weight. It mounts directly to the strut housing for a 1-to-1 stabilizer bar motion ratio, a setup that is usually termed a "direct-acting stabilizer bar" on product data sheets.
Meanwhile, we're not surprised to see the steering rack (yellow) acting behind the front axle centerline -- standard practice on front-drive cars.
To no one's surprise, the Volt's lower control arm (green) is of the L-shaped variety.
A closer look at the aluminum knuckle (or suspension upright, as I like to call it) reveals the pair of caliper mounting bolts (yellow) you'd need to remove when the time comes to change brake rotors. We can also see two of the three wheel bearing mounting bolts. The suspension of the Volt is, at the very least, straightforward and easy to service.
Single-piston sliding calipers (green) and ventilated cast-iron rotors handle the front braking chores. However, like all advanced hybrids and electric vehicles, most of the Volt's light braking needs are handled by reversing the current flow in electric drive motor and turning it into a generator, a process known as regenerative braking.
Because of regen braking mode, our long-term Prius went about 85,000 miles before needing its first set of new brake pads. While it is impossible to hang a specific number of miles on the Volt's front pad life, there's every reason to expect a similarly low wear rate here.
The Volt's rear suspension consists of a simple twist beam axle (yellow).
We've seen twist beam axles like this on plenty of inexpensive small cars. Technically, it's a semi-independent suspension instead of a fully independent one because one side influences the other. And while it may appear that there's no stabilizer bar, the twist beam itself is in reality one gigantic stabilizer bar with wheels on the ends, the roll stiffness of which is determined by the cross-sectional shape and stiffness of the beam that spans from one side to the other. We refer to this as an "integrated" stabilizer bar on our spec sheets.
It the Volt's case the beam is welded to cast-iron ends. The forward pivot bushings are angled so they're not parallel with the beam itself, a move that helps the bushings manage the conflicting need for high lateral stiffness during cornering and soft fore-aft compliance to absorb harsh road impacts.
The shock absorbers mount very close to the rear axle centerline for a near 1-to-1 motion ratio, though the same cannot be said for the springs, which sit closer to the forward pivot point.
A mechanical cable-operated parking brake lever (yellow) actuates the otherwise-hydraulic rear disc brake calipers.
Here's another view of the cable-operated parking brake lever (green) that shows where it resides behind the single-piston hydraulic chamber.
In addition to solid rear rotors, here we can see that the Volt has extended studs that make it easier to mount a wheel and spin the lugs on with less chance of cross-threading. These are common on recent GM models, and it's one of those simple details that we appreciate.
Actual lightweight forged aluminum wheels adorn the Volt, and they wear P215/55R17 Goodyear Assurance tires. Considering the size, the combination is pretty light -- 37.5 pounds -- which means the aluminum front suspension bits we saw earlier were not merely compensating for heavy wheels and tires.
Too bad they don't offer a lot of stick. Our track test of the Volt maxed out at 60.2 mph through the slalom cones and 0.77 g on the skidpad. Braking from 60 mph took 124 feet. None of this is bad, but it's nothing to write home about, either. That's simply what you're left with when you fit low rolling resistance tires to squeeze out as much efficiency as possible, the Volt's primary reason for existence.
93aero says:
08:09 PM, 01/17/11
What, no intro?! interesting!
actualsize says:
09:35 PM, 01/17/11
This is not our Volt, it's a different Volt we had awhile back. That's why this appears in Straightline.
93aero says:
09:43 PM, 01/17/11
touché Edmunds....touché.
6sptl says:
05:35 AM, 01/18/11
As suspension that would make a Suzuki Aero proud. Its embarassing.
throwback says:
05:50 AM, 01/18/11
How do these tires do in the wet and/or light snow relative to all season tires? I would be loathe to run low rolling tires in even a mild Winter.
carguy622 says:
07:06 AM, 01/18/11
Thanks for the walk around. Seems like a very simple setup that, thankfully, handles pretty well.
ed124c says:
07:45 AM, 01/18/11
Dan, I almost understood all that technical stuff. Probably because of (what you described as) a simple suspension design.
Good job, as usual. But I was a bit offended that you had to add, for us non-engineers, the green arrow to the wheel studs. At least you didn't say: (green arrow). That would have been really insulting.
Just joking, of course.
rsholland says:
07:54 AM, 01/18/11
So when are we going to starting reading about what it's like to live with?
s197gt says:
07:57 AM, 01/18/11
i don't have a problem with simple. particularly when it provides the desired results. there is too much complicated for the sake of complicated.
firstwagon says:
08:56 AM, 01/18/11
So is this the same suspension as the Cruze or did it get a more advanced one?
"i don't have a problem with simple. particularly when it provides the desired results"
I'd agree if this car was $20K cheaper.
greenpony says:
10:51 AM, 01/18/11
The car of the future is surprisingly like the car of the past.
half_ton says:
11:59 AM, 01/18/11
The extened studs are a nice touch. Excellent like always Dan.
irvg37 says:
04:27 PM, 01/18/11
this is really an excellent post. on the other hand, volt's suspension is pretty shamefully simple for the price. but i suppose you get the luxury in the form tech....... wouldn't spend my own money on this car.
kevm14 says:
06:28 PM, 01/18/11
"How do these tires do in the wet and/or light snow relative to all season tires? I would be loathe to run low rolling tires in even a mild Winter."
According to first owners who have been hit with snow, it does very well in snow. I was wondering if the tires would be any good, and they seem to be.
"volt's suspension is pretty shamefully simple for the price"
Unless you've driven the car and found the ride/handling combination to be crude or unrefined, I don't think you are qualified to make a statement like this.
cwc1 says:
06:35 PM, 01/18/11
^The ubiquitous Prius has a pretty basic suspension too, since it's based on the bland Corolla (Bore-olla). What one gets instead is some pricey overhyped technology of dubious benefit. Owning a Prius (and probably a Volt too) in the long run is going to be very pricey eight to ten years later when some of that expensive hardware needs replacing and will certainly be obsolete. Perhaps hybrids are better thought of as disposable by that time with no resale value at all.
cah11705 says:
07:05 PM, 01/18/11
I would actually like to do a suspension or break service on this. Looks so simple and even enjoyable to do!
stovt001 says:
10:40 PM, 01/18/11
I think one of the major selling points for the Volt is that beyond the powertrain, it really is like a normal car. It otherwise feels and drives like a nice family sedan. And when I say nice, I mean that in the best way. I actually have driven the Volt, and it was rather pleasant, even by conventional standards. This may be simple, but it really does work.
rsxs says:
04:05 PM, 01/19/11
Is it me or are those some pretty small rotors...
rsxs says:
04:31 PM, 01/19/11
Wow , small rotors
1967oliver550 says:
01:36 AM, 01/20/11
Not 100% sure but these suspension and brake components look an awful lot like the ones on my 2009 Saturn Astra. Simple but quite capable so far.
bimmerjay says:
08:40 PM, 01/20/11
"^The ubiquitous Prius has a pretty basic suspension too, since it's based on the bland Corolla (Bore-olla)."
But the Prius also starts at $21K, not $40K. That's a lot of money to only get a twist-beam axle in back and tiny brakes, but like others have said... you're paying for the other technology. The rest of the car might as well be a Cruze. At least the chromed wheels are forged and not cast like on most cars.
actualsize says:
06:39 AM, 01/24/11
As far as the rotors go, we must remember that a lot of the routine braking (0.2 g and less) will be handled by the regenerative braking system, aka the primary motor-generator. So the pads will only be clamping these rotors sporadically, and they'll have some e-help.
magbarn says:
01:05 PM, 01/24/11
After owning several cars in the past with rear suspension twist beam setups (Tercel/Sentra/Maxima), never going to get one again. Since CA would rather spend tax dollars on welfare queens to spend their EBT cards in Vegas/Strip bars, our on/off ramps have tons of potholes, and a rear twist-beam setup is a horrible suspension for these kinds of roads where you get a rotational/pivot movement on each pothole.
vq35_ser says:
10:35 AM, 01/25/11
I'm not really sure what everyone is complaining about - this is a pretty nice suspension setup. Full aluminum LCAs and spindles. Looks like the rear LCA mount may be aluminum as well. Offset pivot bushings in the rear for excellent lateral stiffness. And extended studs when you want to run 15mm hub centric spacers and go hella flush.
OK, the last one I am joking about but the twisted beam is nothing to shake a stick at. We all know it provides compact packaging, better interior dimension and doesnt degrade the ride. Its a perfectly fine rear suspension. If SL didnt call it out, you wouldnt know it by driving the car.
For those who think the twisted beam is garbage, go on youtube and type in Sentra v Porsche and you'll see me in a lightly modified twisted beam Sentra running 1:38s at road atlanta or chasing down Porsche GT3s. Dont diss the beam
crackheadalley says:
11:38 AM, 01/25/11
About as sophisticated and inviting as my 1984 VW Fox...
magbarn says:
07:53 AM, 01/26/11
vq35_ser says:
10:35 AM, 01/25/11
For those who think the twisted beam is garbage, go on youtube and type in Sentra v Porsche and you'll see me in a lightly modified twisted beam Sentra running 1:38s at road atlanta or chasing down Porsche GT3s. Dont diss the beam
Yes, it's fine on a SMOOTH, WELL-MAINTAINED road course, but horrible in the real world, especially in CA's poorly maintained, potholed road hell we call "roads" In other words for $40K, I'm expecting full IRS not an econobox designed suspension with some Aluminum sprinkles.