Thursday, April 23, 2015

Driving the Volt real world, part 2

Report from April 9, 2015

The volt is not a normal car. Chevrolet is touting it as an electric car, but it does have a gas engine and that causes some confusion in the public, myself included. The natural assumption is that the gas engine drives the wheels directly, as we are so used to that idea from normal cars and even from hybrids.  However, Chevrolet does say the gas engine is a “range extender”, basically a generator of electricity which helps recharge the battery and can power the electric motor. But even their schematics of the drive train show times when the power from the gas engine goes directly to the wheels. However, in real life, I cannot recall ever being aware of the gas engine directly powering the wheels, it is truly a range extender I’ve found.

One nice thing about the Volt is the level of control the driver has over the mode the car drives in. It takes some getting used to but offers the ability to maximize the use of the battery for when it makes the most sense, and employ the gas engines energy when that makes sense. The battery has very limited range, touted at 35 - 38 miles, but this winter it has been 30 miles or less. Again it may be the cold weather effecting the range and snow tires. Regardless, when I drive to New York City, I have found it best to use the Normal setting in town, and switch to gas when on the highway, back to battery, Normal, when driving in NYC.  The Volt allows you this level of control.  The drive settings are Normal, the default setting, which uses the battery until it is exhausted and and switches to the gas generator. In that state, when battery is exhausted and the gas engine is energizing the car it behaves much like a hybrid in that the engine comes on and off depending upon the driving conditions, at low speeds it can be electric, any exertion or faster and the gas engine comes on.  The other drive modes are Sport, Mountain, and Hold.  Sport is as the name implies is truly sporty.  It is great when the battery has a good charge then the Volt becomes truly a nimble vehicle, very responsive and quite fast. Mountain is a strange setting, it keeps the battery half full, so if you are above that, it is running normally with battery power, and it switches to gas when it hits that limit. If it starts out below half full, the engine does double time, both powering the electric motor and feeding electricity to refill the battery.  It is quite disconcerting to have the gas engine laboring away on high, while one is going along at a moderate speed.  The idea is to save enough electric power to help go up mountains and hills.  The other setting is Hold, which simply puts the car into gas mode and saves the battery for when you go back to normal. I have found Hold quite useful for long trips, I engage it when on the highway so it goes into gas mode and stops draining the battery and go back to Normal when in a town setting when one is doing stop and go traffic, and it is nice to not have any emissions. 

This brings me to the weirdest aspect of driving the Volt, the disconnect between the accelerator pedal and the gas engine. One is so used to expecting that when you depress the accelerator, the gas engine responds, it is called a gas pedal for a reason.  However with the Volt there is no direct correlation between pressing the accelerator pedal and the gas engine, and when it doesn’t respond as expected, it is disconcerting. On most cars the when you press the gas pedal you give more gas to the engine. Not so in a Volt. When I go to the Hold mode, the gas engine comes on and runs according to the electric needs, wether to run the motor turning the wheels or recharge the battery when it gets depleted below the level set for it.  So when you are going up a hill, both the engine and the battery are feeding the motors turning the wheels, when leveling out, the engine will still be going full speed to replenish the battery, even though the motor isn’t needing that much power and you have stopped depressing the accelerator.  That is the weird part, the disconnect between what you hear with the engine and the pressure you put on the accelerator. 

April 16, 2015
I purchased my Volt this winter, December 30th, and I got snow tires on it immediately, given my past experiences with a front wheel drive in the snow.  I think that has had a dramatic effect on my mileage, judging by how my car is performing now that I took them off last Friday. I just drove down to New York and back, Tuesday and Wednesday, about 240 miles or so. I’d noticed that the battery showed over 30 miles when fully charged, while all winter it has shown under 30. Driving down to the city, once I got beyond Hudson city limits and it was highway driving, I put the car into the Hold mode, and drove on the gas engine’s power to conserve the battery for city driving.  Even so, over the course of the over 100 mile trip, I was averaging about 45 miles to the gallon, as good as I got with my prior Jetta hybrid.  Once in the city, I cruised along emissions free on the battery power. The garage where I park my car does not have a set up for charging electric cars, but fortunately, I had over 20 miles left on the battery so I was fine for the return trip. On the return trip, I drove out of the city on electric power, until I got to the Sawmill, about 10 miles. I then switched over to Hold to save power for the mountains midway on the Taconic.  By switching on and off the gas through the hold mode, I was able to cruise home getting about 48 miles to the gallon on the return trip, pretty good I’d say!

The volt definitely seems to prefer warmer weather, I'm curious to see how it performs as the spring moves into summer. I'm very happy now with my Volt, I was having doubts, but now realize that its lack of performance battery wise and mileage wise, was due to the cold and the snow tires. Let us see how it fairs this summer.

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