2017 BMW i3: up to 114 miles of range from 50-percent battery increase

For its fourth year on the market, the 2017 BMW i3 electric car gets a huge boost in battery capacity and hence its EPA-rated range.

The battery capacity rises 50 percent, from 22 to 33 kilowatt-hours, and the company says the rated range for the battery-electric version will be up to 114 miles combined.

The range-extended version will get the same battery, plus a gas-tank capacity opened up from 1.9 to 2.4 gallons.

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BMW did not specify estimated ranges for the i3 REx version, however.

In previous model years, its rated electric range was roughly 11 percent lower, implying roughly 100 miles of electric travel for the range-extended model.

With that longer battery range, BMW can "unlock" the capacity of its gas tank—previously limited electronically—to use the full 2.4-gallon capacity, just as the i3 REx already does in Europe.

The new battery fits within the same enclosure and "form factor" as the old one.

The increase in its capacity is due to the use of new 94 Amp-hour lithium-ion cells with higher energy density than the 60-Ah cells previously used.

The 2017 i3's rated output of 125 kilowatts (170 horsepower) and 184 lb-ft of torque from the rear-mounted motor is unchanged.

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So are its 0-to-60-mph acceleration times of just over 7 seconds for the battery version and just over 8 seconds for the model with the 38-hp range-extending 0.65-liter two-cylinder engine.