Last September I traveled to Vancouver to drive the new BMW X5 and was impressed with both the chassis and powertrain. You can read about that drive here. The diesel engine in the X5 35d made me wonder if any other engine was worth the trouble of production. The diesel has mounds of torque along with great fuel economy -- great for a big three-row SUV, anyway -- and I just couldn’t imagine what more you could want. That said, the twin-turbo V-8 is also torque-rich and has big power at the top end, but isn’t quite as fuel-friendly.

I recently traveled to the South of France to drive the new plug-in hybrid version of the X5, the X5 eDrive prototype, and I am now convinced the diesel shouldn’t be the only version built. BMW currently offers an ActiveHybrid version of the 3, 5, and 7 sedans in the United States. All three are powered by a 3.0-liter, turbocharged I-6 bolstered with a 55-hp electric motor. On the current cars, all the electricity is generated onboard, so the hybrid system is more supplemental to the gas engine than fully locomotive.

The top speed on the current hybrid system in all-electric mode is said to be 45 mph, although it takes patience to get there. The maximum range is optimistically rated at 2.5 miles at an average of 20 mph for the smallish 1.3 kW-hr lithium-ion battery. You might be asking what it’s good for, other than silently cruising the Whole Foods parking lot. The idea is to be able to recapture some of the energy normally thrown away while braking and return it in the opposite direction. (Think of it in the same way Formula 1 uses its Kinetic Energy Recovery System.) It works fantastically for that. The electric motor can provide 155 lb-ft of torque starting at 0 rpm, so the boost off the line and anytime the turbo isn’t spooled up adds considerable thrust. The ActiveHybrid system in the 3 Series helps it to be a fraction of a tick quicker from 0-60 mph than a standard 335i while returning better EPA combined fuel economy than a 328i.

The plug-in hybrid serves a different purpose. We’ve seen the technology in more extreme applications from the new i-division, but this will certainly have more mainstream applications. While BMW didn’t give an actual battery capacity, we estimate it closer to the i8’s 7.1 kW-hr pack rather than the i3’s 18.8 kW-hr. With nearly six times the capacity of the current Activehybrids, the X5 eDrive Plug-in will have a full electric range of about 18 miles and a top speed north of 70 mph, and will still do 0-60 in less than 7 seconds. BMW tells us that more than 30 percent of all X5 owners have commutes of less than 18 miles, which would mean those lucky drivers will be driving what is essentially an electric car on a daily basis.

With all the extra electric ability, the I-6 has been replaced with a turbocharged, direct injection 2.0-liter I-4 producing 241 hp and 258 lb-ft of torque. The electric motor is capable of delivering an added 94 hp and 184 lb-ft of torque. Again, we don’t have actual numbers but the BMW engineers at the event hinted that the weight difference between the eDrive and a diesel version is minuscule at best on a 5000-pound vehicle. Obviously the I-4 is substantially lighter than either an I-6 or V-8, plus with the Hybrid you lose things such as the alternator and torque convertor. Also on the list of positives is shifting weight off the front axle with a lighter engine and moving it rearward with the battery pack in the third-row seatwell. Aside from the extra purchase price, it’s hard to find fault with this new powertrain.

I was reminded at a rate of roughly once per kilometer that these were prototype vehicles, and that we might experience unwanted events that would certainly be fixed before production. There were a few things that felt slightly wonky that might not have been as obvious if the engineer hadn’t kept pointing them out. In certain situations, the engagement of the gas engine was slightly less than buttery smooth. If any BMW executives are reading, please keep your engineers out of other manufacturers’ hybrids. They seem very concerned about a system I would still rank as one of the smoothest I have driven. If this prototype wasn’t up to BMW’s standards, the production system will set a new benchmark.

We drove around BMW’s proving grounds on roads that simulated real-world driving as well as on a short technical road course. I was less concerned with lap times as I was with just feeling how it will work commuting and during normal freeway driving. There are three modes available from the hybrid system. EcoPro utilizes full electric mode as much as physically possible and basically requires a conscious effort to get the gas engine to kick in. The X5 is quick off the line and punchy at lower speeds using only the electric motor. Commuting around town would be easily accomplished using nothing but power from the battery. Acceleration doesn’t really fall off until around 45-50 mph. It still pulls, but accelerating onto a freeway would require a little bit of planning or space to get the extra 20 mph needed for merging. Of course, here in Southern California rush hour traffic rarely sees more then 50 mph, so maybe this point is moot for me.

There are other unexpected luxuries in a plug-in hybrid. One is being able to precondition your car on hot or cold days. With an app on your phone you can tell it when you want to leave, and when you get to your vehicle it is exactly as comfy as you would like, all powered off the wall socket. If you have the same routine every day, you’d just set the car to be ready every weekday at whatever time you leave. It’s like telling Jeeves to “ready the car.”

In a hybrid, there is also a different idea about the driving experience. While I love the sound of a big V-8, there is something very elegant in silence and seamless power delivery lacking shifting. Being able to take in the sounds of your surroundings instead of covering them with exhaust notes is very different, but I could get accustomed to it.

Since I was on a racetrack, it seemed like a shame to waste the opportunity. In Sport Mode, the X5 eDrive prototype utilizes electric and gas power together. The small-engine big BMW has power everywhere. Since the electric motor is in the bellhousing of the transmission, it delivers power through the all-wheel-drive system like in any other X5. Coming off of low-speed turns, the electric motor provides instantaneous thrust -- like a cracking of the throttle bodies on a big naturally aspirated V-8. There is zero turbo lag and the transition from the motor’s torquey sweet spot to full boost in the engine’s midrange is imperceptible. I would like to say the hybrid X5 felt considerably different in corners than standard SUVs, but if there is any extra weight, I didn’t notice it. Perhaps the better balance offsets it, or maybe the engineers are telling the truth and the weight difference is miniscule.

A production version of the X5 eDrive plug-in hybrid certainly makes a lot of sense to me. From a driving standpoint, it’s a winning proposition. In some situations, electric power isn’t that much cleaner than gasoline, but in areas where your electrons are coming from wind, solar, nuclear, or hydro, it is certainly cleaner. If you are lucky enough to have a roof full of solar panels, then combining those with this SUV would likely get you on Al Gore’s nondenominational winter holiday greeting card list. At present, no official date is given for the launch of this X5, and I am making the assumption it is a sure thing. If I had to guess, I would put this as a 2016 model-year vehicle. Pricing is another tough one. The current V-8-powered X5 xDrive50i has a base price of $69,125, and I have to think a plug-in hybrid would be somewhere around there, depending on equipment specification. Cars like the i3 and i8 are great for development and early adopters, but plug-in SUVs and sedans are what will get mainstream buyers to make the jump.


BMW X5 eDrive Plug-In Prototype
Base price $70,000 (est)
Vehicle layout Front-engine, AWD, 5-pass,4-door, SUV
Engine 2.0L/241-hp (est)/258-lb-ft (est) turbocharged DOHC 16-valve I-4: plus 94-hp/184-lb-ft front electric motor
Transmission 8-speed automatic
Curb weight 5100 lb (mt est)
Wheelbase 115.5 in
Length x width x height 192.4 x 76.3 x 69.4 in
0-60 mph 6.9 sec (mfr est)
On sale in U.S. 2016 (est)