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Chevrolet Bolt EV Is the 2017 Motor Trend Car of the Year

motortrend.com

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Re: Chevrolet Bolt EV Is the 2017 Motor Trend Car of the Year

#81

Post by phkahler »

Roritharr wrote: post #3

I wonder where the top Speed Limit comes from, is it battery cooling or artificial limiting to proclaim a better Range? In Germany that number raised a few eyebrows.

>> I wonder where the top Speed Limit comes from...

Gear ratio. It says the motor spins to 8800rpm which is high but not crazy high. Given a top speed of the motor the gear ratio will determine the top speed of the car. They may have optimized it for better acceleration at the expense of top speed. Many people in the US never drive that fast so it's not a bad tradeoff.

If you're wondering about having multiple gear ratios, it doesn't make much sense in EVs. These motors already behave in a similar way. For a given (maximum rated) current they will produce constant torque from zero to what is called "base speed" which is the point where the back-emf matches the bus voltage. Beyond that speed it enters an operating region called "field weakening" where some of the current is used to oppose the magnets which is equivalent to reducing the back-emf so it can go faster. In this region it operates much like a constant power device so the torque drops with the inverse of rpm much like a CVT. There's another metric called the constant-power-speed-ratio (CPSR) which is the top speed divided by the base speed. In my experience, CPSR for an EV is likely to be somewhere between 3 and 5 though it can be much higher.

Source: one of my specialties happens to be algorithms for very high CPSR. It's an odd place I never meant to go, but I would enjoy taking a stab at tuning the Bolt.

Re: Chevrolet Bolt EV Is the 2017 Motor Trend Car of the Year

#82

Post by ams6110 »

Klathmon wrote: post #30
archildress wrote: post #22

Earlier quoted context omitted.

This is a great point. Tesla is, to me, fundamentally a battery company.

To me, Tesla feels like a "marketing" company. And I don't mean that in a bad way. Yes, their battery tech is improving, and they make pretty damn good cars, but most of all Tesla is getting people excited for electric cars. Before they came around, electric cars were shitty ecoboxes that were worse in just about every way to an ICE car. They were ugly, had no range, were missing features, expensive, slow charging, e…

Wasn't that one of Musk's stated goals early on? I can't recall the exact words but I thought he had made a statement to the effect that he wanted to show the world what an electric car could be, to raise the bar for all manufacturers.

Re: Chevrolet Bolt EV Is the 2017 Motor Trend Car of the Year

#83

Post by WhitneyLand »

vinay427 wrote: post #5

I'd like to take a moment to point out, as was done in the article, that receiving this award is further validation that electric cars are becoming mainstream. We can compare it to an upcoming competitor (the Model 3) but at the end of the day, they're vying for positions on the same team. That being said, a lot of this felt like an advertisement as another poster mentioned. One thing I would like to see is better ch…

Compatible chargers would be great, but you have the same old problems of a standards war.

Could mathematical tools for fair division help? https://en.m.wikipedia.org/wiki/Fair_cake-cutting

For example it could be used to decide who pays what to buy into the standard, who helps build out the network etc.

Or they could ask Dolby Labs or Sony for help if they really want to lean how to screw up a standards war so everyone loses for years on end.

Re: Chevrolet Bolt EV Is the 2017 Motor Trend Car of the Year

#84

Post by gordon_freeman »

brightball wrote: post #38

I still don't understand why anyone would buy a Bolt (or a Tesla) over a Volt. Since I heard about the Volt initially back in 2006, it was the most logical and practical approach to powering a vehicle that I'd ever heard. Eliminate gas usage on 95% of your driving, but have gas available for long range and fast refueling against the entire infrastructure of the US. Pure EV's are nothing more than "around town" cars i…

Or Prius Prime? The new version of prius plug in would give epa estimated 133 mpge which is the highest number for any car sold in USA. So if you really consider efficiency and even carbon emissions then that is the car one should get. A good amount of electricity is generated in America by coal based power plants so in a way, comparing mpge numbers make more sense while thinking about reducing the carbon emissions. Also found this tool really useful to see carbon footprint of a car.

Www.carboncounter.com

Re: Chevrolet Bolt EV Is the 2017 Motor Trend Car of the Year

#85

Post by cx1000 »

Two questions: the article mentions "magnets made from a rare earth metal called dysprosium" are used in the motor. How rare is this and will it eventually limit volume?

>the wide range of its current and projected uses, together with the lack of any immediately suitable replacement, makes dysprosium the single most critical element for emerging clean energy technologies - even their most conservative projections predict a shortfall of dysprosium before 2015. [0]

My other question, as a non EV, owner is how easy is it to charge these? Can I charge from home or do I have to compete with others at charge stations? At work we have so many EVs that people have to rotate their cars throughout the day.

Note: I'm pro electric car, just curious about scalability

[0] https://en.m.wikipedia.org/wiki/Dysprosium

Re: Chevrolet Bolt EV Is the 2017 Motor Trend Car of the Year

#86

Post by jgust »

Klathmon wrote: post #44
ollie87 wrote: post #41

Earlier quoted context omitted.

Extra battery in the floor of the trailer? Hooks into the car and gives it some extra juice, why wouldn't that work?

IIRC it's not the battery power as much as it is the cooling. Many of the parts on electric cars overheat when pushed pretty quickly, and while adding cooling similar to a traditional ICE seems to be the answer, it adds even more weight and complexity to a platform which is already fighting to save every oz. Even the Tesla Model S can't do more than a single lap around many tracks without overheating.

The diesel-electric locomotive comes to mind. The road has different challenges than rail, but the application is proven.

Re: Chevrolet Bolt EV Is the 2017 Motor Trend Car of the Year

#87

Post by ygra »

cx1000 wrote: post #85

Two questions: the article mentions "magnets made from a rare earth metal called dysprosium" are used in the motor. How rare is this and will it eventually limit volume? >the wide range of its current and projected uses, together with the lack of any immediately suitable replacement, makes dysprosium the single most critical element for emerging clean energy technologies - even their most conservative projections pre…

»Despite their name, rare earth elements are – with the exception of the radioactive promethium – relatively plentiful in Earth's crust, with cerium being the 25th most abundant element at 68 parts per million, or as abundant as copper. They are not especially rare, but they tend to occur together in nature and are difficult to separate from one another.« —Wikipedia

Re: Chevrolet Bolt EV Is the 2017 Motor Trend Car of the Year

#88

Post by brightball »

Vik1ng wrote: post #60
brightball wrote: post #38

I still don't understand why anyone would buy a Bolt (or a Tesla) over a Volt. Since I heard about the Volt initially back in 2006, it was the most logical and practical approach to powering a vehicle that I'd ever heard. Eliminate gas usage on 95% of your driving, but have gas available for long range and fast refueling against the entire infrastructure of the US. Pure EV's are nothing more than "around town" cars i…

https://www.youtube.com/watch?v=5lOV6PdVQbk Consumer Reports touches a bit on that. One advantage is for example that you don't have to worry about the maintenance and reliability of the combustion engine.

I leased a Volt for 3 years to try it out without having to commit to the early adopter risk. Oil changes were every 20,000 miles. Occasionally the engine would turn on and run automatically because I hadn't used it at all in a few weeks just for maintenance sake.

For a gas first approach like most hybrids I think it's a bigger concern. In the Volt since it's just a generator I don't know if the maintenance burden is quite as much of a concern.

Re: Chevrolet Bolt EV Is the 2017 Motor Trend Car of the Year

#89

Post by vinay427 »

35bge57dtjku wrote: post #37

A car that would leave you with about a $600/month payment is 'for the masses'?

"The federal EV tax credit of $7,500 gets the price down to less than $30,000" [1]

"the estimated average transaction price (ATP) for light vehicles in the United States was $33,666 in March 2016." [2]

A car that costs less than the median purchase price for new vehicles in the US seems pretty close to "for the masses" to me. It's at least in the running for more than half of all new car buyers in terms of price (not in size or amenities, obviously).

[1]: Parent article

[2]: http://mediaroom.kbb.com/new-car-transaction-prices-up-2-per...

Re: Chevrolet Bolt EV Is the 2017 Motor Trend Car of the Year

#90

Post by mikkael »

pmarreck wrote: post #63
mikkael wrote: post #33

Surely a nice car. But I wonder where all this electrical power for all those electrical cars in the future will come from? Probably from nuclear power plants with their still unresolved nuclear waste problematics - not even speaking about nuclear accidents. From this point of view I have some doubts that mass adoption of affordable electrical cars will be beneficial for the environment...

1) You're not up-to-date on recent nuclear power safety data. https://www.wired.com/2016/04/nuclear-power-safe-save-world-... http://www.world-nuclear.org/information-library/safety-and-... 2) Wind and solar could accomplish a lot. It already does in Germany, at least.

Regarding 2): Well, in Germany around 29% of the electrical power is currently from renewable energy sources (12% wind, 6% sun, 6% bio mass, 3% water, ...). Not (yet) enough for today and not enough for all future electric cars... https://www.bmwi.de/DE/Themen/Energie/Erneuerbare-Energien/e...
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