BMW i3 Vs BMW Active E Range Test Proves How Much More Efficient the i3 Really Is

With deliveries of its first mass-produced all-electric car — the BMW i3EV –now underway across the U.S., BMW North America is slowly and inexorably collecting the fleet of Active E 1-Series electric cars it has been leasing to customers under the ‘Electronaut’ program.

Does the BMW i3 exceed expectations?

Does the BMW i3 exceed expectations?

Many of those who are handing back their Active E cars after two years of ownership are going on to own an i3 or range-extended i3 REx, but as the outgoing model takes its final bow and heads off into the sunset, several people have come to ask one very simple question.

Is the BMW Active E or the BMW i3 the best car? Which one can travel further per charge, and which one is more energy efficient?

To find out, our very own Michael Thwaite teamed up with well known BMW EV fan Tom Moloughney to find out. The goal: to pit Michael’s recently-acquired BMW i3 EV against Tom’s older BMW ActiveE in a range test.

Charging both cars up to full, Tom and his wife Meredith in the Active E along with Michael and his wife Pamela in the i3 took to the roads in and around Warren, New Jersey, to see whose car would eat through its battery pack first, which car would be the most efficient, and whether new or old was best.

On Saturday, the two teams were kind enough to live-blog the whole experience as they travelled 80-miles in convoy over a wide range of roads, taking it in turns to be the one in front. (You can see the live blog here on our site by following this link.)

Their findings were rather interesting.

BMW ActiveE can go further per charge

Even with an aged battery pack which Tom predicts has lost around 9 per cent of its original capacity, the Active E finished the test with more power left in its battery pack than the BMW i3 EV, with an estimated range of 22 miles remaining after 80 miles of driving versus 16 miles of estimated range after 80 miles of driving.

BMW ActiveE vs BMW i3? Which wins in the range and efficiency stakes?

BMW ActiveE vs BMW i3? Which wins in the range and efficiency stakes?

But that’s hardly surprising, given the fact that the BMW ActiveE has a 32 kilowatt-hour lithium-ion battery pack under its floor, while the BMW i3 only has a 22 kilowatt-hour lithium-ion battery pack.

…But the BMW i3 can go further per kilowatt-hour

If we extrapolate the number of miles driven versus the energy used however, the BMW i3 wins against the ActiveE hands down.

Of course, this isn’t news per say: the EPA recently rated the BMW i3 as the most efficient car on sale today with an EPA gas-mileage of 124 miles per gallon equivalent.

But Saturday’s test demonstrated the abilities of the i3 in the real world. And its lightweight carbon fibre construction comes into its own.

Even with a battery pack a full ten kilowatt-hours smaller than the ActiveE, the BMW i3 ended the test with a predicted range just six miles smaller than the ActiveE’s predicted range.  With less weight to push around, the i3 managed an astonishing 5.4 miles per kilowatt-hour, versus the 4.1 miles per kilowatt-hour of the ActiveE.

The i3 shines in the city, ActiveE on the highway

At low speed, the i3’s lightweight design and efficient power train proved itself far superior to the ActiveE,  starting, driving and stopping between lights in a far more efficient manner than the ActiveE. In fact, Michael and Pamela in the i3 commented how their car’s estimated range shot up in town, overtaking that of the estimated range giving in Tom and Meredith’s ActiveE.

But on the highway, the BMW i3’s blunt nose and large frontal area caused it to lose more energy due to drag at higher speeds than the Active E, proving itself no match for the more traditionally-styled electric 1-Series.

The BMW i3 is quietly revolutionary

While the ActiveE may appear to be the better car for everyday driving due to its larger battery pack and longer range between charges, the i3 proves that electric mobility isn’t just about the miles per charge.

With a battery pack far smaller than the ActiveE, the BMW i3 not only travels further per unit of power — and thus costs less to operate than the previous-generation Active E — but it follows takes less time to charge.

The BMW i3 showed itself more capable in town than on the open road, but still won in terms of efficiency.

The BMW i3 showed itself more capable in town than on the open road, but still won in terms of efficiency.

At the moment, with electricity prices eminently affordable, that might not seem like a big issue. After all, if you’re paying cents per kilowatt-hour, paying for those extra ten kilowatt-hours may not seem like much of a big problem, especially if you get more range in return.

But the i3 is quietly future proof: it hints at a future where electricity prices — like other fuels — slowly rise in price in reaction to global demand. It shows a future where energy efficiency of an electric car is just as important as gas mileage in a gasoline car.

And that’s something we’ve never really paid much attention to before, although we do wonder just how far the BMW i3 would go if its battery pack were as large as that in the Active E. 130 miles? 150?

Perhaps someone with better physical modelling skills could figure it out for us and leave their calculations in the Comments below?

Thanks to Tom, Meredith, Michael and Pamela for helping out with this range test, and to Tom for writing his experiences up at his blog


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