2011 Chevrolet Volt's Extra 'Free' Electric Miles In Gas Mode

Once its initial battery charge is exhausted, the 2011 Chevy Volt seamlessly switches on its internal combustion engine to generate electricity.

But it turns out that the 2011 Volt can sometimes return to electric-drive mode even before it's plugged in, letting it deliver additional “clean miles." Here's how.

According to the very detailed range-traveled display on the center console, once the initial electric drive range is achieved, typically at 35 to 45 miles, the Volt is consistently driven by the gas engine until it is plugged in again.

The range-traveled display records the miles driven by battery, and then the miles added by the gas engine, and the EPA rates the gasoline-driven efficiency of the 2011 Volt at 37 miles per gallon.

However, according to the Volt owner's forum, some drivers see mileage as high as 45 mpg while the gas engine is running.  On a recent trip, our 2011 Volt used only 2.78 gallons of fuel for 122.5 miles of displayed gas driven travel--which computes to just over 44 miles per gallon !

We have regularly seen lower gas mileage, closer to 39 or 40 mpg, on trips taken totally on flat terrain. This more recent 44+ mpg performance was achieved on rolling terrain, and a lucky observation yielded an insight as to how this better mileage is achieved.

The range-traveled display on the Volt separates battery miles driven from gas miles driven. Once the battery energy is exhausted, the gas-driven display is activated and records all additional miles until the car is plugged in again to recharge its large battery pack on grid power.

However, in the recent rolling terrain drive, I had switched the central console display to "power flow" mode which reports in animated presentation exactly where power is going and coming from on a moment by moment basis.  

Not too surprisingly, I saw regeneration braking send power to the battery during any downhill, even while the cruise control kept the car at 63 miles per hour I had set. I was adding battery charge via the coasting and braking process, just as even a standard Prius hybrid does.

However, what surprised me--and it has also now been reported by others on the Volt forum--is that the Chevy Volt, once it has recharged the battery via regenerative braking, will then switch back to electric-drive mode for as much as 2 or 3 miles. BUT, this range is recorded under the gas-driven mileage!

As JeremyK on the Volt forum points out, the extra range comes from recapturing energy first provided by the gas engine in going up those hills. So it's only reasonable that any supplementary electric drive miles be included as fuel-driven, and not from the power provided by plugging in the car.

So, the powerful regeneration in the 2011 Chevrolet Volt adds hidden fuel-free miles to the Volt's total range, which actually increases real-world gas mileage.

The EPA mileage tests do not incorporate this kind of regenerative energy recapture in their standard test cycles, which explains why most new Volt drivers are actually getting better than EPA ratings for their real-world gas mileage.

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