Monday, July 14, 2014

Why I bought a Volt.

Three months ago, I took the dive and bought a 2014 Chevy Volt.  This blog entry is to explain my decision making process.

I'd been mulling over buying a new car for more than a year. My 12 year old civic, while serviceable as a commuter car was getting very long in the tooth.  Also my company took a row of parking spots designated them EV and installed 120v plugs.  With that knowledge I asked myself this question:

"Can I commute completely from work to home in a reliable fashion using the least amount of gas?

My commute is 31 miles each way, so I spend ~2 hours a day in the car total. Half my commute is highway and the other half is stop and go.  A long time ago, as I sat for a half in hour in traffic with the engine idling, I thought "If only my engine wasn't running... how much fuel would I be saving!"

Currently on the market there are a number of vehicles that range from pure electric to plug-in hybrid.
Here's each other car on the market and why it didn't fit the bill for my needs.

Nissan Leaf: While this car would answer my question posed above, there are days that I put 100+ miles on my car.  This would exceed the range.
Toyota Plug-in Prius: Range of battery (11 miles) too small
Tesla Model S: Cost
BMW i3: Cost and newness
Ford C-Max: Range of battery (20 miles) to small and newness.

In the final honest analysis it really came down to the Volt or the Prius.  I chose the volt for a number of reasons.

The Volt is actually an Extended Range Electric Vehicle, (EREV) the Prius is not.  I've had numerous arguments (oddly with Prius owners) regarding this point*. Quite simply, unless some very specific criteria are met, the engine doesn't start.  I could do 100mph on the highway and the engine won't start until I exhaust the battery.  From a practical sense, when I leave my house and the battery says it's got 40 miles worth of charge... I will drive the full 31 miles to work without the engine ever starting. Plugin at work and drive home... without the engine ever starting.  In this regard, I considered my experiment a success.  On an average week, Mon-Fri, I use zero gas.  On the occasion when I do run the car out of battery and it switches to hybrid mode, I get crazy awesome gas mileage.  I've been driving the car for 3 months and I'm still on my third tank of gas!  Who knows, when the MA winter weather kicks in and the battery is subjected to cold temperatures, maybe this won't hold true.  My co-worker who also owns an older volt reported his battery was maxing out a 24 miles in the winter.  However, my car has some enhancements to the battery system his doesn't, so who knows...

From a use point of view, I'm really enjoying the car.  Its comfortable and handles like a dream, when you put your foot on the accelerator your ass sinks in the seat.  The first couple of days it took me a while to completely figure out the driver panel and the center console.  Now it just all works.  My wife while initially intimidated by all the screens, loves to drive the car.

One odd thing about driving the car is how damn quiet it is and by comparison how noisy everybody else's cars are.

Finally, while I expected some interest in the car, I wasn't prepared for the number people who've come running up to the car gushing with a dozen questions.  I almost feel like Chevy should make me an official Volt ambassador or something.

Now, I think I should say something about the drive train... 
* - Prius vs. Volt drive train comparison and conversation.  On several occasions I've had a conversation with Prius owners that goes something like: (PO) = Prius Owner
PO: Your car isn't really an EV because once you get on the highway the engine starts.
Me: No.  The engine won't start until the ~48 mile rage is exhausted.
PO: Oh. But it's still just like my car because it can drive the wheels from the engine.
Me: No, my car is classified as a EREV Series Hybrid.  Your car is a parallel-series blended mode hybrid.  Different animals Yes, under a vary specific circumstance the engine is capable of actually driving the wheels. However, those circumstance only occur if it makes more sense to directly drive the wheels then generate the electricity to drive the wheels.  I suspect (without any proof) that scenario happens infrequently. 
PO: But it still can and there for your car is just a hybrid.
Me: No. It's primary an EV with a backup generator that's capable of directly driving the wheels.
PO: But, but...*gets flustered*
Me: I'm glad you like your car, I like my car, let's leave it at that.  In either case, we're both using a hell of a lot less gas than everybody else.

Here's the cut and paste from the relative wiki article.
Technically the Voltec drivetrain has three power converting elements:[63]

  • Primary traction electric motor/generator, provides good acceleration for driving at lower speeds and regeneration for braking, its maximum output of 111 kW setting the maximum output of the whole system.
  • Secondary electric motor/generator, assists the primary electric motor[64] or works as generator capable of producing 54 kW.
  • Internal combustion engine of 63 kW power,[65] engaged when the batteries reach the predetermined threshold.
  1. Single motor electric - The primary motor runs solely on battery power, maximum propulsion power is 111 kW.
  1. Dual motor electric - At higher vehicle speeds the secondary motor engages over the planetary gear such that it reduces the speed of the primary motor. This facilitates higher efficiency and better mileage for the combined system, without increasing the maximum power.
  1. Single motor extended - The battery reaches its minimum charge which triggers the combustion engine. The engine drives the secondary motor which now works as a generator, via the charging electronics, to keep the minimum battery charge level. The primary motor can still provide its 111 kW for short acceleration, albeit not sustained.
  1. Dual motor extended - The electric motors are used again in dual configuration with increased efficiency at higher speeds. Additionally the gasoline engine contributes propulsion power via the planetary gear. While power is drained from the battery the amount is less than in mode 2 for the same propulsion power, thus extending the range.

These units are connected via a planetary gear and electric clutches to provide power output for propulsion in four programmed operating modes:[63]

Monday through Friday, my car never leaves modes 1 and 2.

In conclusion, my plan was to purchase a vehicle that would let me get from work to home using as little gas as possible and still be usable for longer trips.  The Volt completely satisfies these requirements and to top it all off, is a great car to drive.

As an addendum, the volt is eligible for the $7500 EV federal tax credit.

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