BMW i3 Range Extender

[evnow]

It it was going to be offered everywhere and if Toyota was going to make more than the minimum and then stop (What is it 2,600?) then I would give it more thought and add it to the cars the i3 will compete with, but it's simply a short term compliance car and may even be sold out before the i3 is available here in the States anyway.

At the rate they are selling, I don't think they will sell out anytime soon.

 

[TomMoloughney]

It it was going to be offered everywhere and if Toyota was going to make more than the minimum and then stop (What is it 2,600?) then I would give it more thought and add it to the cars the i3 will compete with, but it's simply a short term compliance car and may even be sold out before the i3 is available here in the States anyway.

At the rate they are selling, I don't think they will sell out anytime soon.

I just looked it up and you are right. Jeez only a little over 200 in 5 months...

 

[surfingslovak]

Scooter-station.com has a few photos of what is supposedly the 647 cc liquid-cooled parallel twin engine Kymco manufactures under BMW license. It's reportedly used in both the C600 Sport and the C650 GT. According to the Autocar drive test drive report dpeilow posted on the Tesla forum not long ago, the i3 "will use a 650cc two-cylinder petrol engine borrowed from its C650 GT step-through motorcycle".

 

[surfingslovak]

The REx was recently quoted with 34 hp, which is about 25 kW of power. That's nice, but what would this translate to in terms of actual vehicle speed? Well, I would expect the i3 to have slightly better aerodynamics than the 2011/2012 LEAF, which had a Cd of 0.29. The outside dimensions should be quite similar. The LEAF owner community amassed an impressive collection of real-world data, and I've listed a few representative mph/kW value pairs below. They were derived from Tony Williams' range chart:

 mph  |  kW
 ---- | ----  
 35   |  5.6
 40   |  6.8
 45   |  8.7
 50   | 10.9 
 55   | 12.8
 60   | 15.4
 65   | 18.0
 70   | 21.2
 75   | 25.0

This data would indicate that the i3 should be capable of traveling up to 75 mph on flat terrain, even if the battery has been depleted. This is pure speculation, but I would think that the generator will recharge the battery, when the driving conditions don't require full 25 kW of instantaneous power. Obviously, the battery would also get recharged through regenerative braking whenever the car slowed down or stopped as well. This accumulated energy could be used to augment the REx on steep inclines or similar conditions.

Personally, I think it's entirely plausible that the REx will provide sufficient power for all urban driving situations. There is a number of interesting things BMW could do here, and the REx, if done right, could be one of the defining features of the i3

.

 

[Parker]

Some more photos showing Rex being topped up with petrol.

http://www.bimmertoday.de/2013/03/22/bmw-i3-rex-erlkoenig-tanken-range-extender-zweizylinder-benziner/

BTW its in German.