Chevrolet Unveils 200-Mile Bolt EV At Detroit Auto Show

MikeChino writes Tesla, take cover – General Motors is taking aim at the affordable electric vehicle market with the brand new Chevy Bolt, which was just unveiled at the 2015 Detroit Auto Show. The all-electric vehicle is able to travel 200 miles on a single charge, and it will cost about $30,000 – which puts it squarely in the ring with the Tesla Model 3. According to the article, "Chevrolet is planning to launch the Bolt EV in 2017, and inside sources say that it will be available in all 50 states."

Comments

nope

[WindBourne]

Oddly, the volt is a gas car in that it is a parallel hybrid. The bolt is a true electric car.

Re:nope

[AikonMGB]

Please stop spreading misinformation. There is a driving scenario where a) the vehicle is operating in "charge sustain" mode (i.e. battery is flat, or user has selected "Hold") and b) the vehicle is being operated at relatively high speeds (> ~50 km/hr) with low torque requirements (i.e. roughly constant speed). In this very specific driving scenario, you are correct, there is a mechanical connection between the gas engine and the wheels.

However, in all other driving conditions, there is no mechanical connection. In stop-and-go traffic around down or on the highway during rush hour, in charge sustain mode, the gas engine will drive a generator motor, the electricity from which feeds the traction motor and the battery -- this is a series hybrid configuration. Under any driving condition while in "charge deplete" mode (i.e. drawing from the battery), the gas engine never turns on, making it operate purely as an EV. An important point to note is that the vehicle is able to achieve is full performance capabilities -- acceleration, top speed, and braking -- under purely electric propulsion without the gas engine ever turning on. This is the distinction that makes it more than just a series+parallel hybrid.

Re:nope

[AikonMGB]

The general problems are the design trade offs that occur any time when there is a direct mechanical linkage between the internal combustion engine and the drive train. The reason is because you are most likely forced to use an engine that has some greater variability in torque and rotational speed than would be necessary if there was no direct linkage.

Why does this matter? Because it likely reduces overall system efficiency. For maximal efficiency, you are better off having an engine that is custom paired to the generator, meaning that it runs at a very confined torque range and rotational speed to maximize generation of electricity since electrical generators generally work most efficiently at a specific rotational speed and fall off on either side of that speed.. This of course requires that the amount of electricity generated is enough to drive the electric motors alone (i.e. no battery support in the case that the battery is dead). By adding a direct mechanical linkage, the engine is likely to require operation over a wider range of speeds and torque and is less likely to be optimized.

Why all this "likely" talk? The video I linked to is the first in a series of presentations by Pamela Fletcher, the head of GM's electric drive train division. She talks about the trades and the systems design that led to what we have now; it's really pretty interesting. Basically they started out with exactly what you want: a traction motor driving the wheels directly, and a generator motor attached to an ICE, with only electricity flowing between them. Then they said "hey wait a second, electric motors are less efficient at higher RPM; can we use this second electric motor to reduce the speed of the first through a high gear ratio, thus improve overall efficiency at high speeds? By golly we can!". That is why the generator motor is able to couple to the traction motor at high speeds to drive the wheels together.

The fact that there is a mechanical linkage when you then enter charge deplete mode is actually a by-product of wanting the ICE connected to the generator motor, but also wanting the generator motor connected to the planetary gear set. It's not something that was baked in from the start as a "core ideal" or goal, it was something that came about as the result of a number of other trades.

The biggest downside to going this route is that there are intermediate periods of time where the ICE will be free-wheeling, which means they required a throttle assembly. If the generator motor were always attached to the ICE output shaft, you wouldn't need a throttle, because you could just cap the RPM using back torque from the generator motor.

Based on the specific conditions that you had indicated for when the mechanical linkage occurs (constrained torque scenario), it is possible that they were able to marry the best of both worlds in terms of efficient engine design, but I'm skeptical. Also, this setup would presumably mean that the individual drive wheels are not directly driven by electrical motors and that there is a drive shaft and differential of sorts in between the electric motor and the wheels. This likely also reduces overall efficiency than a direct drive scenario (i.e. electric motors directly connected to the individual drive wheels).

After warming up, the ICE is generally operating at wide-open throttle (peak efficiency for a given power output). Its RPM is capped by the torque put on it by the generator motor and, when in that situation, the planetary gear set. By adjusting the flow of current (and thus the torque) between the two motors, and using the battery as a buffer for transient events, they can adjust the output power of the engine simply by adjusting its output RPM. Keep in mind that the electric motors are not lossless and neither is charging/discharging the battery. Any power going from the ICE output shaft to the drive shaft mechanically is not subject to the losses of going through two electric motor

Re: Only 30 Grand?

[mrchaotica]

Just for reference, the average-priced car is unaffordable by the average-income household.

Re:Bolt or Volt?

[ganjadude]

no, the volt was actually updated today as well - http://www.autoblog.com/2015/0...

they are 2 totally different cars. But the new volt is looking pretty awesome, this bolt kinda looks like a mix between the BMW i3 and the chevy spark

Re:Competition?

[ganjadude]

dealer networks. Technically tesla could sell in all 50 states if it wanted to play by the rules in place. I dont agreee with those rules and hope tesla wins, but tesla knows what it needs to do if it wants to sell to the masses

Re:Auto Dealerships to distribute the Big 3 autos.

[dbitter1]

which seems poised to place this vehicle in front of more potential customers than the Tesla.

Meh. Tesla sells every single car it makes and has a waitlist backlog months (or years for the M/X) long. That is with NO advertising. Whoopdy do, more eyes.

Additionally, Tesla has the (current) checkmate of the supercharger network. I know that likely won't be free to the M/3, but I assure you it does a great job of squelching range anxiety... something the other guys remain hobbled by.

And for the commuters... I welcome *ANY* (safe) electrical vehicle at any price range. We will fix the coal/gas power plants later, and it will be transparent. Lets get these ICE cars out of here. WAAAY too much energy lost in the ICE reaction. Especially for city driving, regenerative braking is a lifesaver... think of not only individual vehicles, but city busses... large vehicles ideally suited for high torque electrical motors, where regenerative braking can recover a lot of that.

Re:Price needs to come down

[andydread]

The batteries in the Prius last typically longer than 10 years. Im not aware of *any* electric or hybrid vehicle that requires a battery replacement "every few years" Did you bother to do any research or did you just make that up?

Re: Only 30 Grand?

[mrchaotica]

Isn't that to be expected? If the average car is a used car, then the market will move to cover that average with the average household income.

While that makes sense, the claim of the article is that car prices are rising relative to household income -- in other words, it implies that the average new car used to be affordable, that it now is no longer so, and that it's continuing to become increasingly unaffordable.

Also, when you demand only the absolute top end fuel economy and space-age safety features, yeah, your car is going to be expensive. Especially when you use legislation to require both of those, since it means zero competition encouraging the higher end models to come back down to earth with more regular pricing.

This, I can agree with. There's no legitimate reason why cheap, lightweight cars like the Honda CRX (better fuel economy than a modern Prius... in 1988!) are effectively no longer allowed to be made. (And before somebody tries to use something like an Elio as a counterexample... it's not. It's a damn motorcycle.)

But please tell me how the average person can't afford a $200 a month car payment with minimum wage set at $1980 a month.

That's a strawman argument: the average household can indeed afford a $200 per month car payment, but that $200 per month is only enough to get you a cheap, lower-than-average car! The article never made any claim that the average household couldn't afford a car at all; only that it couldn't afford an average one.

It's also a strawman for a different reason: the minimum wage is not $1980 per month! First of all, $1980 / 160 hours (full time for a month) = $12.375 per hour, which is simply wrong. Federal minimum wage is actually $7.25 per hour, which would add up to $1160 per month. Second, federal minimum wage is per hour, not per month, and most minimum-wage workers aren't allowed by their employers to work a full 160 hours per month even if they want to, so the minimum "monthly" wage is even less than that.

Re:Cost?

[swillden]

Tesla would seemingly need the battery cost reductions from their "GigaFactory" to get the cost of their 200-mile electric car down to $35,000, and Chevy is going to sell a 200-mile EV for $30,000 without those cost reductions?

Something's gotta give to pull that off.

Nissan's 2016 LEAF is going to have a 200+-mile range, and will also be sub-$30K.

Re:Only 30 Grand?

[Anonymous Coward]

No one will admit to it,... but either OPEC is trying to destroy the US Shale-Oil business by pushing the price of oil through the floor.

It's really weird that you feel like no one will admit to it, and that it's speculation "on your part". This is widely known. It is not a secret. It is a workable and working strategy. This is not a conspiracy theory, it is reality. I've seen probably a dozen articles on it, and it's the topic of discussion on both NPR and conservative talk radio. Rest assured, the price will rise again.

The saudi's paid some very smart investment analysts to determine the burn down rate of new wells, pipelines and capacity in north america, and compare that to global markets. Their reserve value will outlast the shale oil investment costs, you can be sure. They also decided to punish the other OPEC states for previous non-cooperation in price fixing at the same time, and this will cause those competitors to deplete reserves faster too. It's a triple win for them. Win/win/win.