2014 BMW i3: One Lap of Orange County Range Test
January 30, 2015
Last week I drove our 2014 BMW i3 hatchback around my One Lap of Orange County test loop, a 105.5-mile course that tours around the rough perimeter of "the OC" without ever setting foot on a freeway.
This loop was first conceived as a replacement for the city test course we drove as part of our Las Vegas-based Super Sipper Smackdown tests. We wanted a similar course we could use more often without having to deal with the logistics of a road trip.
As such, what's best characterized as a "suburban city loop" was never conceived with electric vehicles in mind. At first we tended to use it for hybrids, a class of vehicles that maximizes city mpg by means of regenerative braking. And because they're pretty much a poor man's hybrid, the course also makes a handy way to test the effectiveness of automated Stop-Start systems.
But we quickly realized our "One Lap" loop works very well for EVs, so long as a truck and trailer are waiting to collect the test car and haul it back to our metered charging station. The arbitrary length of our lap is by no means a pass/fail standard, but pins on a map marking the point where the trailer was called in (or the remaining range for those that reached the finish) make a handy way to illustrate differences.
Now that our 2014 BMW i3 (with range extender) has made the trip, we have data for just about every electric vehicle you can name. The regular BMW i3 — the one without the optional range extender — took its turn last fall.
Here's how they did.
2014 BMW i3 (no range extender)
EPA rated range: 81 miles
Edmunds OC loop range: 95.8 miles
Difference: 18% surplus
2014 BMW i3 range extender (aka REX)
EPA rated range: 72 miles
Edmunds OC loop range: 87.6 miles
Difference: 22% surplus
It's not unusual for us to beat the EPA-rated range that appears on an EV's window sticker on this loop. Their procedure is quite conservative when it comes to electric vehicles, and for good reason. Optimistic claims have no place when buyers could run out and become stranded after purchasing a car that takes some hours to refill.
But why is our i3 REX rated lower than a regular i3? After all, it has the same 22-kW battery. For one, the optional range extender increases the car's weight by some 270 pounds. On top of that, the i3 REX is programmed to bring the engine and generator on-line before the juice runs out. The reserve that results ensures there's enough on hand if a high demand situation crops up.
Fine, but this range difference used to bother me. Was our purchase of the range extender version a mistake? Why pay more to give up 9 extra miles of EV-ness?
After this test, I don't think we did. The REX doesn't have less electric range, not in any real-world sense. In fact it drives like it has more because there's zero range anxiety down near the bottom. It's easier to go deeper into the battery of an i3 REX.
In the regular i3 test loop the 85-mile mark came after the first of several increasingly persistent "plug in soon" warnings. Range anxiety would have been in full swing if I hadn't had a trailer shadowing me. It would be very unsettling to run a regular i3 down to 10-percent full on a regular basis.
Meanwhile, 87.6 miles was just a number that I recorded in the logbook when the engine came to life in our i3 REX. The draining of the battery was a non-event with no anxiety, no warning lights and zero consequences.
Our i3 REX simply switched modes and cruised on to the finish line like any other car. The faint gray fuel gauge bars brightened up as the blue electric ones faded to indicate that gasoline was now running the show.
In the end I rolled into the gas station that marks the end of the lap and added less than half a gallon of gas.
BMW i3 REX EPA range extender mpg: 39
Edmunds OC loop range extender mpg: 36.9
Our observed fuel economy in range extender mode fell a bit short of the EPA gasoline rating despite driving with the same care that beat the i3's rated EV range by some 20 percent.
We saw the same sort of thing with our 2011 Chevrolet Volt. Apparently the care and caution that's applied to the EPA's electric vehicle range rating goes out the window when it comes to gasoline fuel economy ratings, which is no surprise. Still, 36.9 mpg in the city is a pretty decent number for a back-up generator system that brings with it a lot of peace of mind.
Dan Edmunds, Director of Vehicle Testing @ 1,135 miles